Why do I randomly have glitches, black screens and barely opens?

i’m young i dont really know what to do i use this macbook air for school projects and presentations. While doing my schoolwork it randomly pops up a black screen but i can see a small line on the edge of my screen that you see in like movies where its like numbers but i can barely see it because its just a line, so what i usually do is i restart it but when it opens i can see glitch patches and when i tapped on the touch pad it added more glitches, i restarted again, it opens it goes on okay but everything happens again BUT now when i open it the screen is now frozen and then i restart same thing again pls help my parents will get mad at me and im scared btw chill-tab pops up often as well PLS HELP ME