I'm not at that level, but maybe I can get away with wiping with $20s right now. Something to shoot for I guess. Discipline is gonna be important for you, as is staying the course and not getting spooked. Those two things will quickly derail any financial plan.
Multiple banks can be handy if you have a lot of money, and/or if you have better interest rates which some do. But the problem is that most, if not all banks, pay 1% interest tops. Not very competitive.
Hit up /ck/ if you need some food tips for a budget. I'm a hobby cook as well if you want a second set of eyes/ideas.
Credit works on a few factors: negative marks on your account, number of accounts you have open, account balances relative to your credit limits (Credit utilization), and the age of said accounts.
Negative marks from things like medical debt or missed payments can sit for up to 7 years.
More than likely, you're spinning tires in the 600s because you owe money, you don't have years of open accounts under your belt, and/or you have a high amount of credit utilization. That is, you have CC balances or loans that are close to your limits. In that respect, having more than one credit card is good, even if you don't use it much. It shows lenders that you have a high amount of capacity before you hit your debt limits.
Creditors hate my kind because we pay our balances in full, have extreme limits on our card, but never get close to maxing them out.
They also consider revolving debt versus installment loans. Revolving debt carries less weight when they look at your history. Installment loans like mortgages, car payments, etc. look great on you when you pay them off for good.
You can always drop me a line on Discord too if you need some really detailed advice with either finances or food.
I'm gonna rest though, see you around!