Question today i put my pc in sleep mode and it booted by itself and change my desktop background to a picture of kobe bryant

Well just kinda wondering if you had been viewing any Kobe Bryant picture or news stories? Not that that would be the reason for your desktop picture to be set as you said.

Are you being pranked, brother or something?

Check your task manager what is going on in there.

Once pranked my mother and put a desktop picture that had a warning that if she pushed any button her Mac it would explode.