Q: Spinning

Hi there, claudiawats.

Thanks for using Apple Support Communities. It appears that after updating your MacBook Pro to OS X El Capitan, it's stopped working smoothly as you'd expect. I'll be glad to help!

Try safe mode if your Mac doesn‘t finish starting up -- Safe mode will make sure your Mac starts up correctly. Test how it responds in Safe Mode. If there are no issues, reboot normally and test in your own user account.

OS X El Capitan: If your Mac runs slowly -- This article provides areas on your MacBook Pro you can check.

How to test an issue in another user account on your Mac -- If the issue is also happening in safe mode, use this article to test another user account. This will demonstrate if the issue is isolated to your account, or if it's system wide.

Let me know what you find and take care!