Many are under the assumption that since it it DIII baseball, they can walk-on. However, that is a misnommer. Most DIII programs actively recruit, some more than others. Some use a shotgun approach, not noing how will actually show up, and others try to recruit their needs.
In any case it is still competetive baseball.
I would take piaa_umps advise and make contact with the coach and see if their is an interest.
As far as playing ball and keeping up with your studies, that depends upon the student.