No, first step is to get a USCF racing license, or if you want to just try it out, you can get a 1-day license at most races that have Cat 5.

If you find Cat 5 too slow, enjoy your brief stint of domination before upgrading, but I'm guessing this won't be the case. Not saying anything about you as a cyclist, it's just always faster than you think.

Bottom line is you'll never know till you try, and you have to race in that first race at some point... Enjoy!