Great question. Am going to answer this from an angle of the musician and self-promotion, as I've been doing my own concerts for over 20 years. I started my music career in a college atmosphere as well, so I understand well where you are coming from.
There is a lot to this question, and could be answered several different ways pending on what your goal is.
First, I would ask yourself one simple questions "why" do you want to get into the promotions business? What is it that you are trying to do? Help Musicians? Are you a musician yourself? Make Money?...There are no right or wrong answers, but it's all about poking into the driving force or inner passion behind this endeavor.
You mentioned getting experience and seeing if its a good fit. Do you have any friends that are musicians? Since you are at Ohio State, there are probably many many artists doing shows around the campus. Start by helping one of them with a local show. Do the basic stuff - post flyers, email posts etc, but MOST importantly... get to know what the artists really want/need for their show...what venues to they want to play in? Coffee Shop down the street? Book stores? Then just walk over to these places and start talking. You will learn so much by just talking to other businesses as well. Get to know the people who owns these businesses and ask questions about what would help them? Have they always wanted a solo guitarist to set a mood in their coffee shop? You have the person for them. Get a website going...Start Simple...start small. Build relationships.
You are really in the perfect situation as you have a wealth of supply of artists (within a college campus) who are wanting to get their music out there, and I am sure there are many supportive venues that are willing to book them. Go to one of them whose music you really like, and offer to help them. They will so grateful, and you can start to learn this business from the ground up.
Again, there's a lot to this question, but hopefully this gets you on a good path.
Am happy to chat on the phone with you as well. Good Luck!!