truth is, no one is going to win a cat 5 race because of a fancy bike or gear. It just doesn't matter.
One of my first races when I was starting up, the 3rd place finisher had regular shorts and t-shirt on a really cheap, heavy Schwinn Varsity type of bike. I don't think he even had clipless, just sneakers.
He made a move, got a gap and held it. Good instincts. He came out with his family, had a great time.
On the opposite end, another guy I rode with got caught up in all the tech hype. I gain X watts with tubulars, X watts with this, this many seconds, blah blah blah. He actually said, "I feel like I'm cheating with this advantage I have over everyone else."
That changed once he raced. He DNF'd, and I think the reality put him off racing.
Cat5 is about having fun, going out there and finding out what it's all about.
Don't be gunshy and don't bury your nose in a computer.
Crits are intervals. The best training are fast group rides and interval training.
Plenty of rest before the race, and make sure you have fun.