Does it affect my credit if I cancle my unused credit cards?

Answer 1

If it doesn't cost you anything to keep these open, it is better to leave them be because it can enhance your credit score to have all that unused credit still available to you.

Answer 2

Cancel the unused ones. With open credit cards, the lender knows that, say you have 5 credit cards with a $5,000 max, that you could easily run up that much more debt and have less money for paying a mortgage. Keep 1 or 2 of the oldest ones and do use at least once a year.