Open a bank account as soon as possible after your arrival. This will make it much easier to organise monthly payments such as rent and insurance.
Account maintenance fees are usually charged for a bank account. However, most banks and savings banks offer current accounts free of charge for students - ask for a student account.
In Germany people tend to pay in cash - especially for small amounts. Credit cards are relatively widespread but are not often used for everyday purchases.
On the other hand, payment by cash card is very common.
Foreign driving licences are valid for stays of up to six months in Germany. However, you may have to provide a German translation of your national licence or an international driving licence.
After six months non-European driving licences are mostly no longer valid. Thereafter, you will most probably have to take the German driving licence.
More on the validity of foreign driving licences (in German only)