Register in the city of Weimar
After your arrival and as soon as you receive your rental contract, you need to register as a new citizen of Weimar at the Residents' Registration Office . You don't need to make an appointment in advance, but you should bring your rental contract as well as the so-called 'Wohnungsgeberbestätigung' filled in by the landlord.
The confirmation of registration will be important for the application for your residence permit (Aufenthaltstitel) and to open a bank account.
If you are not a citizen of the EU, of a EEA country or Switzerland, you need to change your visa into a residence permit (Aufenthaltstitel).
For this, you need to make an appointment with/at the Immigration Office (Ausländerbehörde) before your visa expires. Write an email to terminvergabe.abh[at]stadtweimar.de
As the residence permit is valid for only a limited period of time you might have to prolong it during your stay. Please contact the International Office regarding the required stamp on your enrolment certificate.