Hi, there!
First of all, welcome to Tier 10!
Second, I'll echo what someone else already mentioned about only 2 games at T10 is just barely scratching the surface. At tier 10 you will see a higher proportion of veteran players than you will at 5-8. These players tend to be more conservative and not "yolo" the way that new and eager players often will. This will feel a bit like they are "camping" (and sometimes they are), but often they are waiting for the right moment to take advantage of a situation. Destroyers are critical at T10 because they spot things for allies to shoot, so if destroyers aren't doing destroyer things, it will make the match feel more drawn out.
I encourage you to keep it up! Petropavlovsk is likely the hardest cruiser at T10 to punish hard, so don't give people your exposed sides, use your AP rounds more than you'd think, and don't push too far too soon!