congratulations on your certification.
Given your limited time, I would suggest that you try to find a job at a gym. That gives you a chance to observe other trainers and get your name ‘out there’.
Getting a business going is quite involved. You need to register a business and get your liability insurance. You will have some upfront cost and may not be able to recover that if your availability is limited.
I wish you good luck.
Congratulations on your certification! Since you are new as a trainer and have limited time, I do agree with Karin that employment at a gym is a good idea. Starting your own business takes time (to establish and grow), and does cost some money. Also, it would be very helpful if you found someone who can serve as a mentor for you to show you the ropes and answer questions.
Another avenue for you is employment at the university where you are enrolled. Given the fact that you are an athlete there, studying kinesiology and just got certified, you may inquire if there are any suitable positions there–or perhaps you can make a few connections that way.
Owning a business will require a lot more time than you have available at the moment. I agree with the others that the best option for you right now is to get a job at a local gym and expose yourself to as many clients as possible. It will be a great experience which you can use later when you’ll have you own business. Starting and operating a business is very complicated process and if you don’t have the experience or the right people to help you set up your business, it will be difficult for you to grow it. I’m not saying it can’t be done, but if you are going to do it it’s better to get it done right from the beginning.