Are you entering the Western or English riding program?
I completed the western program 1997-2001. I'd recommend you get all the basics - go for inexpensive grooming & bathing supplies that can be replaced as needed, but aim for quality halters, leg wraps, saddle pads, and girths. Look for easy-on-the-hands lunge lines & lead ropes (cheap nylon burns!), and invest in heavy duty, quiet running clippers. These items will get lots of use, often on multiple horses each day. Quality materials will prevent you from the need to replace things too rapidly.
If you have any questions, especially regarding saddles, bits & headstalls, I'd highly recommend waiting until you arrive to speak with the instructors. They will help you find the best quality that fits your budget; these things are an investment for your career.
In my time there, the first several weeks was ground work only, so you likely have time to find a saddle. In either English or Western program, you'll be working with multiple horses throughout a semester, so your saddle will just be padded up/down to get the best fit on that particular horse.
Good luck at Findlay! I LOVED my time there.