There are dozens of ways you can prove for yourself the earth is not flat and that supports a spinning ball. Take an astronomy class, for one. And read several of my posts, such as this one about the size of the sun. Since the sun does not change size, that simply eliminates the possibility of a flat earth entirely, and is consistent with an earth that has a sun that is so incredibly far away that there is no 'parallax' even when people are 6500 miles apart.
There are dozens of other things you can test for yourself that will support a spinning ball. An astronomy course is an excellent place to start.