Get better and play better competition

Hello everyone! I play Rocket League on PS4. I've been playing since Rocket League came out (with the exception of a two-year break while traveling). I've been back and playing, currently ranked Plat 3 D 2. In my opinion, I'm better than my rankings (which everyone says) but I've only ever really played with my two brothers. They are okay at the game, but I wanted to try playing with some better people because I think I can contribute more and get better playing with better competition. I understand rotations well, I'm more than willing to take advice/feedback from anyone so I can improve. Hope to hear from you.