My screen types gibberish and randomly selects things itself!

Heya, I have an I pad mini. There are no visible cracks on the outer screen and the touch response is 80% working. However, I've found that the i pad randomly types or selects things itself or zooms/unzooms itself (glitching out basically, it almost seems like it's been remotely controlled/ hacked but it isn't because gibberish is being entered into the search bar lol). Additionally, certain areas of the screen are unresponsive. Particularly in the bottom right corner, I noticed there seems to be a fine scratch/crack under the outer glass in that area- I'm guessing that the LCD may be damaged? Also, be noted that the display visually, is perfectly fine. So my question is from my description, would you know if I need the screen or LCD replaced please and thanks :D