It's usually more fun to do challenging races with other racers who know what they are doing. I think new racers, or any racers, should do the most challenging races available to them as long as they are not so far over their head that it's pointless or dangerous. So, do that, and upgrade when you get enough points so you can increase the challenge.

"Politics" are really a non issue. It's a hobby, get the most out of it. One thing I can say with confidence is that you will increase your enjoyment of bike racing by obsessing less about upgrade points or what other people think of you.