Im in college, this is my first semester and I was just wondering. When you have an expense that has'nt been paid for what do you do? Does it go under the expense and the accounts payable?

Yes, the jounal will be:
Debit the appropriate expense account for the amount
Credit Accounts Payable for the amount.

When the bill is paid the journal entry will be:
Debit Accounts Payable for the amount of payment
Credit Cash for the amount of payment.