I sell on Etsy.
They do not take care of taxes for the seller.
There are different tax rules for every state, so you would have to research your own state to see what they want.
For now, my advice is to keep track of every sale,
and every in-state sale. Also keep track of any expenses, like Etsy fees, shipping costs, packing materials. In short: everything you paid out related to your business, and everything you took in related to your business. Google "Schedule C" to find out what you need to keep track of.
Then when tax time rolls around again, you will be prepared, and not scrambling for information.
Tax software like Turbo Tax and HRBlock both have modules set up for online sellers, when you get to that point.
There are online sites that help you keep track of all this, one of them is Outright by GoDaddy. But there is a subscription fee of course.
Hope this helps