what gamemode is best based on rating?

so i just started chess like a year ago on chess.com I haven't played that much chess games but for the pas few weeks i have so my real question is since I'm rated 400 should I play bullet blitz or rapid like you know what time mode from 100-500 500-1500 1500-2500

If you don't care about improving, play whatever you find more fun. If you do, play rapid 15+10 or longer.

I'd avoid bullet entirely at this stage.

When you want a quick fun game, play blitz - but still analyse your games afterward to get value from them.

Playing longer time controls like Rapid will be best for most people. Personally, I still improved quite a lot playing predominantly blitz, but I supplemented my training with solving tactics, endgame drills and generally learning strategy.