Touchscreen is working by itself

@mukhammady54778 if you are referring to things like opening Apps by itself etc, then the issue is most likely related to something called "Ghost Touch". It originates from a failure between the digitizer and the rest of the screen. You will have to replace the screen assembly. Since iFixit does not yet have a specific guide for this, use something like this video as your guide. Replacement screens are readily available and not to expensive. Just do an online search and select a vendor that appeals to you.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!