How should I invest $20,000? Should I invest some in CDs and some in stocks?

Dear Quentin, 

I’ve just moved to the U.S. to join my family, and I have about $20,000 in my bank account, and I’m not sure how to invest it. I have no need for the money at the moment, but I’ve applied for a master’s program and want to fill out a Free Application for Federal Student Aid (FAFSA) form.

My child, who…