Hi guys. I was wondering if i make a app what license should i get?

You can use the personal version (the free one) of Unity to publish any game either for free or for a price. Unity only requires you to have the pro version if your game makes over $100,000 or receives funding of over $100,000 (USD).

The only other legal things you would have to worry about is copyright and the type of content in your game. If you included copyrighted material in a game you are making money off of, you will probably have issues. I'm not 100% sure about this, but I think you can put copyrighted material in free games.

If your game has a lot of graphic, sexual or racist material in it, you might have problems publishing it to the app store, but it really depends on where you are publishing, and what the rules are.

Hope this helped