@SaarebasThis is my first time GMing and I suggest a good Co-GM. I honestly could not have done this half as well without Kronshi keeping me on track sometimes.
Set up rules that work for you and stick with them, even if you have to do the sucky part of politely pointing things out to people that certain things don't work or they need to fix.
Let people know that they can ask question, correct you if you are wrong because we are all humans.
Let them knew that if they have a problem to come to you.
Let people know that you want them to share ideas to make your RP a part of theirs, that they equally have say in the directions and movements.
Not sure what other advice to give XD Not a very great GM myself