If you've already signed your lease on your USF apartment, you have two options. The first option would be to terminate your lease early. Your specific lease contract will let you know what the consequences are for ending your lease early. You may have to pay the remaining rent, pay the rent until a new renter is found, or pay half your rent. (This is just one of the many reasons you need to read your lease carefully and understand it before you sign!)
Your second option would be to sub-lease your USF apartment. Sub-leasing is where you basically rent out your apartment to someone else. They pay you rent (which you then pay to your Tampa apartment complex). Some leases strictly prohibit sub-leasing; in which case, this option is obviously not for you. Many apartment complexes want to know who lives in their units, for various reasons. Discuss your plan with your roommates, if you have any, and make sure they are agreeable to a sublease.
If you decide to sublease, there are a few things to keep in mind. First of all - always have a signed, written agreement between you and your sub-leaser. State how many people are allowed to live in the apartment, whether pets are allowed, if smoking is allowed, if you will be leaving your furniture for them, and other considerations. Include the dates that they will be living in your apartment. Also include whether or not bills are included in the rent, and how these will be paid if they are not. Take pictures of the condition of your apartment before you leave. Have the person you sublease to fill out a form noting the condition of the apartment with both of your signatures. You can find pre-made subleasing forms online, most of which are a good starting point. Your specific USF apartment may have their own forms that you and your sub-leaser must sign.
Choose the person you want to sublease your apartment near USF to carefully. In most cases, you will be responsible for any damages they may make. Requiring a deposit isn't unheard of. You can charge the full amount that you pay for rent, or less, if you think you may have trouble finding someone to live there. If they stop making rent payments, while they are still responsible to pay you, you are still responsible to pay your landlord. You may want to have a background and/or credit check run before you accept anyone. Your landlord may be willing to help with this.
There are several websites that you can advertise your sublease on. You can also post fliers on campus. Additionally, let people you know that you want to find someone to sublease. Word of mouth may find you a great sub-leaser. However – if you do end up subleasing to a friend, have them sign a contract – no matter how good of friends you are.
If you decide that subleasing is the right option for you, start advertising about two months before you want to move out. Most people have some idea of their summer plans by March.