If you have enough room at your home to set it up stay over night in it there. If not I would pick a close park & do what we call a shake down weekend. Don't overload your mind with all the great sites that have been posted for you education now. Too much info is just as bad as not enough. Just stick to the basic sites that hddecker has posted now. As far as what to pack I have my RV set-up with bedding, cloths, dishes, and the like that stay in the RV. My RV is my earthquake shelter.
Take along a note pad for you first time out & write down what would be nice/needed to have along.
If you haven't backed up a trailer I would find a RV park that had a pull thru spot. You can always go out & find a big parking lot & practise backing at a later time.
#1 thing is to enjoy your time RVing. Yes you will forget items & make mistakes. Even us that are veteran RVers have. Don't ask me how I know.