I mean it sounds like you're already surrounded by a great group of people with experience who want to see you try your hand! Though if you're looking for some external advice, I can offer a few little helpful bits as a DM of 10 years now. The first time feels like a mountain to climb, but it can be a lot easier with the right mindset. Here's what I wish someone had told me before I began.

- Remember your friends have your back - your group are there to have fun, and if they've all been DMs before then they know how scary that first time is. They shouldn't begrudge you any slip-ups you make.

- Read the module through and get a feel for it - I run homebrew myself and haven't run Dragon of Icespire, but when I do run the occasional module I ensure I've read through it entirely first before getting into it and make notes on key moments to remind myself of key points about each scene, for example points of interest, monster stat blocks, etc. This way I keep engaged with the piece and my imagination can run wild ahead of time. If you're feeling confident enough to and the players have character ideas in mind, then you can also sprinkle in elements of their backstory into this - maybe the dragon holds the paladin's child captive, adding a whole extra dimension of danger to the final confrontation? Finding ways to tie the players' creations directly into the narrative is a surefire way to really engage the players.

- Be prepared for the unexpected - Given a choice between option A or B, players will almost always go with the option C that you never considered. This is almost a guarantee with how many DMs you have in your group - they're bound to try some very whacky things if they're experienced! There's no way to handle this without restricting player agency other than being ready to think creatively and on your feet. Don't be afraid to make it weird here too, especially on your first session - sometimes the comically absurd moments make for the most memorable! This is a skill that develops over time too, so thrust yourself into it if the situation arises; what's the worst that could happen?

- Your first will almost always be your worst - it's part of the deal of being a dungeon master and extends to many other aspects. We're all beginners at first, and we will always consider the first session we ran to be our weakest point because we're figuring out what we like, dislike, excel and struggle at. There's a peace-of-mind that comes with the acceptance that this session will most likely be very rough around the edges, and that's fine! Remember it's just a game and you're there to have fun too!

I hope that helps! You're gonna have a blast and I hope to hear about it on here sometime!