Does anyone have in-depth knowledge of credit score?
I just need to spend, okay?
But do I have to repay the entire amount each time, or just the minimum?
Paying the minimum is the requirement, paying more helps. Paying the whole thing off is often not the best approach.
Here's a hypothetical positive use example:
Get a credit card and put nothing on it except gas.
Let's say you spent $100 on gas in one month.
You'll get a bill saying you owe $125 (because interest) and your minimum required payment is $25.
You *must* pay at least $25. If you don't, your credit will go down, plus you'll get credit card specific penalties (fees or threats they'll close your account).
The best thing you could do is instead pay most of it. $80 or so. You would then owe the remaining $45. This will help your credit the most.
The next month repeat the process.
Put another $100 on the card for gas. You'll then owe $175 (100 gas + 45 balance + 30 interest).
They'll say your minimum required is around $40. This time try and pay $120ish.
Whatever your maximum credit line is (the max you're allowed to put on your card), you always want like 15-25% of that owed on the card at any given time if you're trying to build credit. The minimum payment is usually just paying off the interest you've acquired, not the purchases you've made. If you need to financially it doesn't hurt you to pay the minimum, but it doesn't really help your credit much.