Since you already have a rig I imagine you're wondering how to use it. That's simple, like the advice given to new hams first listen, listen and listen some more. Once you separate sanity from insanity choose your path wisely, make up some sort of unique identifier like a "handle" no one else in the area is using and when someone asks your "20" the name of your town is quite sufficient.
The only rule is common sense, don't be an idiot and you'll do well. Just a few basics come to mind like:
Thou shalt not use illegal equipment, if you want to be "worldwide" get a ham license.
Thou shalt not talk with a fake Texas twang, your Martian accent will do nicely.
Thou shalt not use 10 codes or speak silly CB jargon, plain English is easily understood.
Thou shalt not drone on endlessly when signing off, goodbye is sufficient.
Thou shalt not say seventy threes for 73 (best regards) unless you want to invite someone like me to return with "Yeah, seventy fleas, scratch sixty nine but save one for later when you really need one."
There should be 10 but I ran out of ideas, if I think of more I'll get back to you later.