I've been thinking about this while out of town and I may have come up with a slightly better, more detailed approach:
1) Pick an event type, sanctioned by body A, or unsanctioned (often modeled after KCBS).
2) Download the rules for that sanctioning body and/or event and read them enough so that you can take a test on them.
3) Plan your setup. Pick cooker(s), a travel vehicle, gear, and a way to move it all around. For gear, you can find free checklists on line, or write down all the things you use for your practice cooks. Oh yeah...
4) Do at least one practice cook. This is expensive and time consuming, but you'd hate for your first time out to be your first practice. At the very least, this will give you a direction on where you are going with scheduling and gear.
5) On your gear and your practice cook, remember that weather changes and things go wrong. Prepare for hot/cold/rain/dark. "cover" and light are a must IMHO.
5) Work out a schedule. Figure out how long it takes you to cook things, ask if you are going to hold things hot or cold, and count backwards. Your schedule should include everything starting with what time you show up, and everything you do from then until you go home. No kidding. Again, you can probably find some for download.
6) You might wanna practice again. Just sayin...
7) Depending on your budget and what you can see yourself doing, take a class. There are several out there in several differen price ranges. Most of the top ones are in the off-season, but some are year long.
8) When you don't know or have a question, search here and ask. You may not get (helpful) answers, but asking won't hurt.
Don't forget to stay hydrated and have fun!
dmp