I'm a first year student at UMES, so I'll do my best to answer. We had to "dress up" on Tuesdays for one class in the first semester, which meant that we had to buy a white lab coat (around 30 bucks), wear khaki's or slacks and a nice top, and men had to wear a button-up and tie. This semester we have to wear white T-shirts and black shorts for labs, two days a week, but no more dressing up in nice clothes.
Otherwise we wear whatever we want. Most people wear workout clothes. 2nd and 3rd year a bit different, and they have to wear nicer dress clothes more often because they start going into the clinic and have more presentations and practical exams.
Have at least some khakis or black dress pants, professional FLAT shoes if you're working with patients, several nice blouses or button-ups/ties. Dresses and skirts are optional. Some classmates definitely wore dresses and skirts, but most went with pants. Pants are also more versatile if you're working with patients as well (I'm assuming, I haven't worked with patients yet). You shouldn't need much more than that, especially for your first year, unless your program specifically tells you what to purchase.