If your car will pass tech and is generally safe and in good running condition, consider it done and stop worrying about it. You can look up the requirements on the internet.
If you want your first time to go more smoothly, go research autocrossing on the internet. Videos of runs, personal anecdotes about racing, guides for newbies on what to expect and how to get started, all this stuff is easily available. If you don't want to do that you could probably just show up and start asking lots of questions. I prefer to know what I'm getting into ahead of time so I researched it.