Welcome to the forum.
Get rid of Clean My Mac, it has been known to do a lot of harm and doesn't do anything that cannot be done much more safely. If you think you must have a "cleaner" on your Mac, then get OnyX, from here:
https://www.titanium-software.fr/en/index.html Get the right version for your version of the OS. It is free and it works well. But frankly, I don't "clean" my Mac at all, it's not needed.
When you shut down, you should be seeing a prompt like this one. Make sure the box is not checked.
Also, open System Preferences>Users & Groups, click on the little lock in the low, left corner and type in your password when prompted, then click on Login Items box and you will see what you have installed to open on boot. If there is anything there you do NOT want to open, then click it once to highlight and the click the "-" symbol below the window.