If you are going to be doing business under a trade name or plan on selling any taxable product you
should get a business license from your state department. Here in Washington it is like $50 for a sole proprietor license. Setting up an LLC or S-Corp will save on taxes in the long run, but isn't really worth it unless you are making six figures off the business, they are also much more complicated to set up.
If you don't you will have the IRS to deal with. aaaannndd....
The government likes their tax dollars. You could go sole proprietor > LLC > S-Corp as you scale your business but the point is you should have a license of some kind no matter what state you are in. (Unless you do everything in cash, bitcoin and barter and just
not report your earnings, but you can't leave a paper trail)
Doing so can also protect you from say if you were to be sued from loosing personal belonging in a lawsuit. Whereas if a business is sued you only risk business assets. (Keep your personal and business bank accounts separate).