This might be a cliche question, but do you have any tips for a first-time DM? I'm planning on running Lost Mine of Phandelver with friends (when I finish reading it) and it's intimidating to say the least.
You are going to make mistakes and that's ok!
If you find that your players want to do something that you are unable to account for or is outside of the scope of what you have prepared, you can always be honest with them and say that you wouldn't have that particular concept prepped or that its outside of what the adventure has.
Make sure you have all your materials prepped in advance. Your maps drawn out, the tokens you plan to use for the characters, etc. If you don't have minis and you want to use minis, a super easy and cheap option is to print out paper minis. You basically print them on cardstock, cut them out, and glue them onto a little base! I wouldn't go too overboard on the arts and crafts as a first-time DM.
If you're playing online, then you'll want to use a service like Roll20 or FoundryVTT to act as a virtual tabletop to represent all the stuff that you're doing. I would NOT recommend doing theater of the mind if you are playing online because people are much more likely to get distracted or lose focus.
There's a million videos and blogs on game master tips and advice. I don't agree with all of it or use all of it, but that's because you're not supposed to. Every DM does it differently! Every group is different! Not every suggestion is applicable to every game! But it's still worth looking up advice because that's how you get exposed to new ideas.
Oh! ALSO! Look for videos and online guides for Lost Mines of Phandelver. Every officially published D&D adventure has a ton of people going "here's the good parts, here's the bad parts, here's how to properly run it". For a smaller adventure like LMOP, they can cover basically every major encounter or concept which is super useful.
Here are a couple of videos I found by quickly searching that I recommend:
https://www.youtube.com/watch?v=lRQZEYAgxGM&ab_channel=VerdigrisTable-RyanDoyle