Server customization help

[Cloudn9ine]

Hello! I'm currently working on a server i hope to accomplish in making into a public game, but the first thing is that im new to hosting a server of my own, and i would like to receive help as in tips and ideas for certain ways id like to customize my ss13 server, i just want to know how to do things like add in game music, make rounds, add remove certain concepts and items, add custom maps (if theres a way i can add an already made map i would very much like that) and create roles for other players to be able to play, if anyone knows how to do any of these things i would very much appreciate the help C: im also looking for people to choose as admins so if you see yourself as a responsible person for such a role ill gladly put you as one of my recommendations.