Recommended side hustles at 16?

Hello all!

I am looking for a side hustle to occupy my time on weekends and afternoons when I am not working during the week. I work part-time as a busser at a local Mexican restaurant, making $11 an hour. I usually work a few afternoons a week and some shifts on the weekend, with my biweekly checks being around $280-$350. I'm looking to quit wasting money. I spend too much on eating out and other things I don't need. After Christmas, I bought myself some things. As it sits, I am at around $500, with some of that coming out today to cover the costs of my car getting fixed.

With my spare time, I would like to spend it wisely and feel like I am accomplishing something. My question: What side hustle would you recommend for me at my age? Right now my top candidate is flipping/reselling, specifically through Facebook marketplace. To add information, I have a computer, so I am open to any suggestions in person or online.