The first thing which you need to do is obtain a copy of your credit report.
You are entitled to request a credit report for a year. It is advisable to make use of this service to make sure that there are no issues that you may not be aware of.
Errors should be resolved as soon as possible. If you have outstanding accounts or fees you should make every effort to make payments. All of these efforts will help to improve your credit score so that you can secure a lower interest rate on all forms of credit.