What is a law clerk

Looking to go back to school and change careers, thinking about getting in to law. Can anyone tell me a layman’s version of what a law clerk does? Also, if you think being a law clerk is awful, is there a different area of law I should look at? The closest Ive come to a court is telling my ex to hire xcopper when he got a stunt driving ticket, so I have actually 0 idea on what aspect I may want to be involved in.

Just looking for a 9-5 that keeps my brain active, but less compassion fatigue than I’m facing in animal medicine