You know for sure that credit report is a mirror of your credit activity. It contains the information about the length of your credit history, the types of credit you used, your personal information and your outstanding debt. The more attractive your credit card report is to the lender, the better credit deal you can make. As for credit score, it is a number that shows how trustworthy as a potential customer you are. If your score is high enough, you can get cards with lowest interest rates, fee free, rewards and other attractive features.
To know for sure that everything with your report is ok before applying for any card, you need to order your credit report and score. Once a year you can do it for free. And of course, it is only in your interest to check your credit score and report at least before you apply for a new credit card or a loan.