Before leaving your native country you should check if you can tick off all of the following points.
Citizens of non-EU/EEA countries must apply for a visa that is valid for the city in which you plan to stay.
Your passport must be valid for at least the duration of your stay in Germany. Depending on your native country even a validity for 3 months longer than the period of your stay is required.
The address of your flat in Germany is required by some authorities.
- Health Insurance
Whether your home insurance covers all necessary expenses in Germany or have to apply for an additional insurance policy?
It is recommended that you carry some money with you when arriving in Germany. You will need it i.e. for local traffic tickets. Also some hirers charge a fee for their appartments.