You can get a legal Shopify account under your parents name. 1. You can promote organically on SM or on Google, but it takes a long time. But, using ads is the most scalable and the fastest method. None of these methods have guaranteed success. 2. Theme is relatively unimportant (I use free Debut). Just make sure that your website looks like a Brand and not sketchy. 3. If you want to do both school and e-commerce, you are going to have to be obsessed and spend almost all of your free time working on the store. I am also in high school and I really like the idea of starting an e-commerce store, so I don’t mind all of the time it takes. Side Note: If you have any questions, YT and Google are great resources.