Idle temps are perfectly normal for windows 10. There's enough crap that runs in the background, that constant program startups will constantly bounce your temps from idle 32 to small load startup 55. But thats such a small load that the temps drop a second or two later, no worries.
It's the 90 that's the issue. With just 2 fans, airflow isn't optimized and that tiny CoolerMaster isn't much more than a 'stock cooler' would be. Ok for websurfing or other light cpu usage, but under duress, plain sucks.
Airflow needs to be better, adding fans is good idea. If going with an aircooler. Aio has included fans, so the budget becomes more equitable. Honestly, I'd slap in a fractal design Celsius S36, 360mm radiator, for a cleaner look with full front matching fans, move the current intake to exhaust and never worry about temps again.
Oc is a hobby, very rarely ever a necessity. It's a little performance tweak you can do yourself to push the performance envelope. It's not much more than fine tuning the cpu. But simple as it sounds, to do right is quite complex and there's a multitude of variables to consider. Airflow and cpu cooling ability are just 2,theres voltage limits current limits other voltages that may or may not need changing, compatability with eco settings etc etc. That involves a lot of research, and when you think you have read everything there is, read it all again. Figure every definition of every setting in the bios, what each setting does, what it means, how does it affect other settings etc.
Then go play. Baby steps. Test. Change things. Baby steps. Test again. A good OC can take a week to attain and another month to dial in better. As I said, it's a hobby, take the time to do it right and it's worth it. Skip steps, jump big, change things you don't understand and what you'll get is not much different from a load of other posters all wanting to know why their pc keeps bsod in the middle of a game.