Best plan to earn as much college credit as possible??

Hey guys, I’m a junior and I just discovered taking college online classes at the nearby community college to rank up on some credits. I’m taking 3 AP courses and I’m not taking AP USH because I skipped that in IB last year…

I know very little about this process and I was wondering what you guys did to earn a lot of credits. I can’t receive much scholarship or financial aid because of my parent’s occupation so I’m very dependent on these credits so I won’t end up with a large student debt.

Can you please tell me how you did it and and how much money/time you saved? How was college after that?
I’m applying to UCB and generally the UC system so if anyone has connections with them that would be very helpful. Thank you!

This question is very important to me because I only have 2 years left which goes by very quickly.

Bump. I need tips on this, too.