First things first. The "dumb" questions are the ones you don't ask. None of us knew the answers when we started, either.
Second of all - there are a couple of campgrounds in the Wendover megalopolis - a KoA and one right behind/next to the Stateline I mean Nugget casino. But there is free camping that's absolutely unlimited and very "primitive" - no utilities - and free and no reservations needed. There's no camping on the salt per se, but at the Bend in the Road is where there's no limit, no charge. More data if and when you ask for it.
Pre-registration is simple enough -- find the SCTA website and click around to the Bonneville section and find the entry forms. Print, fill, and mail. Or use the one where you can fill it in and submit online. No paper and Stan Back is happy with you.
That's enough for a while. See you on the salt.