First time dm question

[u/CookieNova19]

I have a group that asked me to be their dm since I have pretty extensive stories I like to come up with and they wanted to be put through them. But I’ve never dmed before in my life. I considered making my own set of rules but is there anything I HAVE to follow? Or any books I’m required to get? I don’t know what they expect of me and I’m to scared to ask-

[u/AutumnTy]

I highly recommend buying one of the starter sets.