Automated Testing

I can see it's making sort of an on-ramp where people can incrementally develop their skills. So we talked a little bit about what that first test is checking that the start screen comes up. But let's say we have an existing application without any real automated tests. How do we come up with a list of the things that are going to be testable with automation versus what do you stay away from and say, hey, we're not going to tackle that? I think a good starting point is implementing maths, which is minimal acceptance test suite of a test suite.