Kudos for taking the reins at that age! As for which path to take, consider that any startup requires an initial investment that you probably won’t make back fast. Ecommerce and dropshipping seem like easy wins, but nothing is devoid of challenges today.
If you’re aiming to work from home and build an online-only business, I’d suggest you taste the waters by selling your skills first. Make profiles on various freelance hubs and learn from the more experienced members. See what’s in demand, what is a so-so reliable model ROI-wise, how should you set things up as to not run things into the ground soon, etc. Once you got the know-how and have a clear roadmap in your head, consider investing in your own brand.
Good luck!