Please apply for a visa at a German embassy in your home country well ahead of your planned arrival. You will need a visa in order to live and study in Germany.
a country with differing regulations concerning visas (e.g. Honduras, Iceland, Monaco, Norway, San Marino, Switzerland, Liechtenstein and USA).
Information on visa regulations in Germany can be found on the webpage of the Federal Foreign Office. There you will also be informed if you do need a visa or not.
Do not arrive in Germany on a tourist visa! It is impossible to convert it into a residence permit!
Make sure you apply for a "multiple entry" visa for Germany.
Frankfurt (Oder) is a border town and you will most likely want to cross the border at some point during your stay as there are not only dormitories situated on the polish side. Also a lot of lectures are held there / taking place there in the common /corporate institution of the European University Viadrina and the Adam Mickiewicz University, the Collegium Polonicum. Due to this fact you will have to apply additionally for an entrance visa to Poland. Please contact the Polish embassy in your home country in good time.
Please be sure that you apply for a "multiple entry" visa, too.
Information about your rights and responsibilities as foreign citizen residing in Germany can be found on the homepage of the Foreign Student Advisor Dr. Carmen Thiele.