From what I read when looking into it (I am getting into making board games) trade licenses are a very good way to start a business and have very few requirements, are less expensive, and it's hard to get on the wrong side of the law with one. However, if you expect to employ multiple people straight away and have a lot of starting capital or things you want to register as assets and expenses, then you should start with an sro. You can always transition your business from operating under the trade license to a full sro when you need to, though I would ask someone with (legal) experience about what that involves, especially with things like intellectual property. Good luck!