Hello!
I have to pay a housing confirmation payment for the University of Southern California and I want to know if I am able to use my financial aid to do so. If possible, how do I USE the money they have gifted me? I got enough financial aid and I am unsure upon how to actually use this money for the housing payment.
Thanks! 
You have to ask them if you can use FA for the housing deposit. If they allow it (some schools do not allow FA to be used for the deposit), the FA office will be able to process it for you.
I don’t think they dispense the FA that early. Even if you can use it for that purpose, you would have to pay it out of your pocket first. Did you check if they have put any aid in your account yet? For certain aids, they cannot dispense until the semester almost begins.
When you received your financial aid award letter from your school, did it show that you/your family is expected to pay $xxx.xx amount of your college cost? If you are not very, very low income, the housing deposit is something you are expected to pay and it will go toward the total family contribution.
What did your letter say?
I would just pay the housing deposit. For most USC students, even those on large scholarships, it shouldn’t be a prohibitive cost.
Call the FA office and ask them. You’re not the first student with this problem and sometimes schools have short(ish) term, interest free (or low interest) loans that can help you float until your FA is dispersed.
How much is the housing deposit?
Do you qualify for a Pell Grant? If so, call the school and see if they’ll waive the deposit. Many schools do waive it for Pell Students.