In my left side of the screen I have some pixels are dont work perfect

Try taking the phone apart, before you undo the crews turn the phone off (THIS IS IMPORTANT, I LEARNED THE HARD WAY) before you rip the screen off there should be some ribbon cables, mark where they are and use a flathead screwdriver to pop them off (BE CAREFUL!!!!!!!!!!!!!!) then use a clean brush and clean both the phone connection points and the connectors on the cables replace the screen and turn it on, if the problem persists try buying a new screen from ifixit