I put google play store on my grandsons kindle (not rooted). I used my account and I also made an account for him as well. Now I want to take my account off and leave his on there. Is there a way to do this?
Not sure if it will show up on a Kindle (since it's not a Google Play certified device), but you'd need to do that from the Account settings on your device. There just remove the Google account in question.
IF such settings aren't available, then you can just log into the Play Store on a web browser with the account you want to remove, go to you Device Activity, and just remove access from the device you want to deactivate. https://myaccount.google.com/device-activity