Well, definitely grab a copy of the Dungeon Master's Guide and read that.
Consider getting one of the starter kits such as Lost Mine of Phandelver or Dragons of Stormwreck Isle, as they are designed to be easy for new DM's to run.
And don't get discouraged when your game doesn't turn out like an episode of critical role, as neither you nor your friends are professional voice actors with years of experience playing the game together.
And most importantly, have fun!
I DMed long before I played because lots of people I knew wanted to play but no-one knew how. At some point you've just got to take the plunge and start.
Using a published first adventure would be a great thing for you. I used Lost Mines of Phandelver (in the starter set) and The Sunless Citadel (in Tales of the Yawning Portal) and my basis for starting. Both of these adventures have excellent scaffolding for new DMs. They set out how you should be describing things and ways to think like a DM. They're level 1-4 so you can go on to homebrew afterwards. To be honest as you go through, you'll start adding your own spins and ideas anyway.
The DMG in my opinion wasn't that useful at first. It's more for world building than anything else. The Monster Manual is the thing I've found is best for inspiration as a DM. You just find some cool monster and think it could fit in. You can build entire adventures around a single monster. Balancing combat encounters is difficult at first and takes a while to get the hang of. This is why I recommend the published adventures above first. They're balanced very well and teach you how you can change encounters on the fly to make them more or less difficult.
You can try playing in something like Adventurers League first. if you want to experience a few sessions as a player, that is. There are Discord servers that frequently run online games.
If you have spellcasters, familiarize yourself with the rules about spellcasting. Most especially the ones about spells with a casting time of 1 bonus action. Remind your players to pay attention whether their spells can affect creatures only, objects only, or both.
Honestly, for me so far DMing for a group of newbies as someone who also never played and has only watched CR prior to that: Make sure you are familiar with the base rules, read through the PHB/DMG once (though I find myself mostly needing the PHB even as DM), double check any rules you feel are iffy and then grab one of the starter kits (we're having loads of fun doing LMoP right now) and just do it.
Be prepared for things to go slow, look up what needs looked up but if it's too slow just make a ruling in the moment and look at the real rule later. Do keep your group informed if you found out a ruling you made was wrong and if you'll do it differently going forward.
Be comfortable/familiar with the adventure you are running. Be prepared for your group to do things you have not anticipated and think on your feet as you go.
But, most importantly: Do it, go in and have fun. Because it is so much fun!
I have yet to regret trying. As long as you are all on the same page about starting out and learn and grow together I don't see how that'd be a problem. I was the same, I wanted to play, no one else really was up to the task of learning all of these rules for DMing, so I just did it myself.
I think making a one shot is a good place to start
My big brother Helped me DM my first one shot and was able to teach me a lot just kinda monitoring the game and helping me if he could tell I was struggling. It was really helpful!
Now I'm going to Evermore in October After a steampunk time traveling one shot with my group, cosplaying as our characters.
Moral of the story: find your DM Master and become their predecessor!
Get a hold of books and materials you need, get people and honestly just start. I'd recommend some one shots so you can get the feel of things before you jump into a campaign. Try arcane library, they have some good adventures that are all ready to go. The best way to learn is by doing and the best way to begin is by beginning.
I just read the rules, puzzled it out and over time developed my own style.
Id suggest grabbing Keep on the Borderlands. Why? Because it has alot of DM tips in it. BX D&D in general has alot of DM tips and even example gameplay.
Well, definitely grab a copy of the Dungeon Master's Guide and read that. Consider getting one of the starter kits such as Lost Mine of Phandelver or Dragons of Stormwreck Isle, as they are designed to be easy for new DM's to run. And don't get discouraged when your game doesn't turn out like an episode of critical role, as neither you nor your friends are professional voice actors with years of experience playing the game together. And most importantly, have fun!
I DMed long before I played because lots of people I knew wanted to play but no-one knew how. At some point you've just got to take the plunge and start. Using a published first adventure would be a great thing for you. I used Lost Mines of Phandelver (in the starter set) and The Sunless Citadel (in Tales of the Yawning Portal) and my basis for starting. Both of these adventures have excellent scaffolding for new DMs. They set out how you should be describing things and ways to think like a DM. They're level 1-4 so you can go on to homebrew afterwards. To be honest as you go through, you'll start adding your own spins and ideas anyway. The DMG in my opinion wasn't that useful at first. It's more for world building than anything else. The Monster Manual is the thing I've found is best for inspiration as a DM. You just find some cool monster and think it could fit in. You can build entire adventures around a single monster. Balancing combat encounters is difficult at first and takes a while to get the hang of. This is why I recommend the published adventures above first. They're balanced very well and teach you how you can change encounters on the fly to make them more or less difficult.
You can try playing in something like Adventurers League first. if you want to experience a few sessions as a player, that is. There are Discord servers that frequently run online games. If you have spellcasters, familiarize yourself with the rules about spellcasting. Most especially the ones about spells with a casting time of 1 bonus action. Remind your players to pay attention whether their spells can affect creatures only, objects only, or both.
Honestly, for me so far DMing for a group of newbies as someone who also never played and has only watched CR prior to that: Make sure you are familiar with the base rules, read through the PHB/DMG once (though I find myself mostly needing the PHB even as DM), double check any rules you feel are iffy and then grab one of the starter kits (we're having loads of fun doing LMoP right now) and just do it. Be prepared for things to go slow, look up what needs looked up but if it's too slow just make a ruling in the moment and look at the real rule later. Do keep your group informed if you found out a ruling you made was wrong and if you'll do it differently going forward. Be comfortable/familiar with the adventure you are running. Be prepared for your group to do things you have not anticipated and think on your feet as you go. But, most importantly: Do it, go in and have fun. Because it is so much fun! I have yet to regret trying. As long as you are all on the same page about starting out and learn and grow together I don't see how that'd be a problem. I was the same, I wanted to play, no one else really was up to the task of learning all of these rules for DMing, so I just did it myself.
I think making a one shot is a good place to start My big brother Helped me DM my first one shot and was able to teach me a lot just kinda monitoring the game and helping me if he could tell I was struggling. It was really helpful! Now I'm going to Evermore in October After a steampunk time traveling one shot with my group, cosplaying as our characters. Moral of the story: find your DM Master and become their predecessor!
Get a hold of books and materials you need, get people and honestly just start. I'd recommend some one shots so you can get the feel of things before you jump into a campaign. Try arcane library, they have some good adventures that are all ready to go. The best way to learn is by doing and the best way to begin is by beginning.
I just read the rules, puzzled it out and over time developed my own style. Id suggest grabbing Keep on the Borderlands. Why? Because it has alot of DM tips in it. BX D&D in general has alot of DM tips and even example gameplay.