> the more you use your credit card and pay it back on time, the higher your score gets

No.

Paying on time is good for your score. Paying a bill of $0 is exactly as “on time” as paying a bill of $10,000, and has exactly the same effect.

Actually using the card is, at best, irrelevant, and at worst (temporarily) bad if your utilization becomes particularly high. Though utilization is not remembered month to month, so it’s not something that needs to be managed unless you are actively trying to get a loan.

So long as the card isn’t so inactive that the issuer closes the account, using it or not doesn’t matter.