? about raising or lowering your credit score

It's hard to say without knowing your income. What a credit rating assigner will factor is on time payments, and income to debt ratio as well as debt potential. Having five credit cards even at zero balance could be a bad thing depending upon your income. Do some research on preferred income to debt ratios for credit ratings and go from there. I can tell you I have excellent credit and have not had a credit card in 10 or 15 years so one card won't hurt.