I can help!
You're a C cat, so start in C. You'll be competitive and towards the front of the race in a strong Cyclechat team. You'll get a kick out of seeing your team mates around you and it will help drive you on. And you'll be helping the team to score points.
If that results in you getting promoted to B, then that's the way it goes. But, moving up is a big step. My first race after getting promoted to B cat in the feltet.dk series, I was blown out the back after the first km and then rode a 34km individual time trial, which is a lot more depressing than competing up the front end of the race. My second B race, I started much better and managed to get into the last group on the road and stayed with them to the end. So I felt much better and contributed a single point to the B cat team for finishing.
Carl had a very similar experience when he rode the first race of the series as a B cat, and then stepped down and rode competitively in C cat.
So my advice is start as C. If you form is good you'll contribute well to C and if you earn promotion move up then and help me out at the arse end of the B cat race!