If you encounter slowness or errors on your WordPress site, your plugins might be the cause. The easiest way to troubleshoot this issue is to disable all of your plugins, and then test your site.
There are two ways to disable your plugins depending on whether or not you can log in to your WordPress dashboard:
If You Can Log In
You can disable your plugins in WordPress. For more information, see Activating and deactivating plugins in WordPress.
If You Cannot Log In
You can rename your plugins directory (and create a new one) so WordPress cannot access your plugins. This lets you log in to your WordPress account again to troubleshoot your site. After you’ve resolved the issues, you can delete the new directory and rename the old directory so WordPress can access your plugins again.
Learn more about troubleshooting plugin issues in WordPress