everyone I unlock my screen it will go to a black screen then it goes to the play store

[Justinmichael4u]

I have a ZTE max pro running marshmallow and everyone I unlock my screen it will go to a black screen with a small loading bar at the top of the screen then it goes to the play store I also have found an app in my app settings and it has a blank white logo and when I get into it I am not able to uninstall or force stop and I checked my device administrator and it was one of them and it was activated and I was able to deactivate it. Can anyone help me out please