how much $ can one earn before it affects grant money for college?

There isn’t a clear answer for you. Your elligibility for grants such as the Pell Grant are based on your income, but I think also on the size of your family, cost of attending your chosen college, etc…

The best way to find out is to check at your chosen college’s financial aid department and let the professionals walk you through the process.

The website below is the official website for the FAFSA application that you will have to fill out. There is loads of information there.