I'll try to give you a serious answer, My first job when I turned 16 was a grocery store cashier and it was honestly so boring and a bit too strict. The store I worked at you were not allowed to lean against anything or sit down while working, you could not have drinks which is terrible since I usually worked 8+ hours at a time, no phones, etc. I think it was a great first job to get you accustomed to the "work experience", but since you're wanting a chill job I'd have to say Lifeguarding. I worked as a lifeguard over the summer and it....amazing. Little to no work, all the lifeguards I worked with complained about always having to clean and go up on stand with only 2 people in the pool when I was more than happy to. Who doesn't want to get payed $10 an hour to sit? If lifeguarding isn't an option (since you must get certified, and pools might be closing for you.)
I'm going into delivery for a restaurant down the road from me, $7 an hour plus tips, I talked to some guys who deliver their and they said it's not hard at all if you have a phone/gps/good with local roads.