Starting a business is hard enough in the best of times, but this year Etsy made changes to the search function that are making it difficult for small scale sellers to compete. That's on top of global uncertainty and shipping cost hikes. There's also been a rash of mature listings recently, so you should probably avoid unsupervised browsing. Etsy has increasingly been putting holds on seller money, which might happen to you as a new shop. You will need to plan for losing money at least during that initial period. The post office raised prices and is beginning to delay packages (intentionally, not incidental Covid delays). IMO, there has never been a worse time to start an Etsy shop.
Keep in mind that you will have to do bookkeeping and figure out your local business laws. This may mean applying for a business license and/or paying taxes (or at least doing tax paperwork). You'll need to budget for packing materials. It's cheapest to buy shipping labels online, which requires knowing how much your items weigh when all packed up for shipping. You'll need a bank account (it may need to be your parent's since they will be the responsible party for the shop), and your parent will probably have to verify their ID. You will not be allowed to use the Etsy forums/community spaces until you are 18.
I've been on Etsy since nearly the beginning. We have a history, not all of it good.
Maybe donate a portion of your earnings to a bird welfare association?
