What happened to my laptop? :<

Hey guys, my laptop experienced some weird tech issues today during online teaching. After 5 minutes of having my laptop open, everything froze, but I could move my mouse freely. The strange thing is, when I tried to put it into sleep mode (by closing the laptop), and then opened it again, it started running normally. However, after 10 or 12 minutes, it froze again, and I had to close and reopen it to resolve the issue. Can someone help me out? I'm currently using a Dell laptop