Keep spinning won't start up

I am guessing this is an app. You can try going into your settings and click apps, then clear the cache. If that does not work you may need to reinstall the app.

See if you can start the tablet in safe mode or in recovery mode. You can do this by turning on the tablet and holding either the vol-up or vol-dwn button at the same time as the power button.You may need to look for the exact process. It varies between models but because it is using android there should be a way to do so. Once in safe mode or recovery see if it will let you boot into safe mode, or try and reboot from there.