Hello and welcome to Android Forums. Hopefully I can help you with your problem.
You have several options but the most sure fire way to fix that issue is to do a factory reset. You have that option both in the stock recovery and custom recoveries if your device is rooted.
You also have the option to go into your devices settings, look under apps, and then look for Google Play if that is the vending app you have on your device. Tap on it and choose to wipe or clear the data.
Without knowing what device you have, it's going to be hard for me to troubleshoot it. The options I have given will more than likely fix your issue.
Another option you have is to look up your device here at Android Forums and see if it is supported. If so, I recommend joining and seeking help in your device's section.