Hoses and belts damage
Even if you don’t know too much about engines, you can still pop open the hood and do some reconnaissance. The various hoses and belts that you see should all be free of cracks. Of those that you can’t see, it is possible to identify potential problems simply by keeping the hood up, turning on the engine, and listening for sounds. If anything makes a squealing sound, or there are any repeated clanking noises, then there is probably something wrong.