Contact the citizen line under 040-42 82 80 if you want to reach relevant offices in Hamburg.
Foreigners' Registration Office („Ausländerbehörde“)
Residents’ Centeral office Hamburg
Hammer Straße 30-34
Citizen's Office („Bürgeramt“)
In each district of Hamburg, there are so-called Customer Services (“Kundenzentren”) in which administrative services like registration are provided. Here you can find all their addresses.
Social Welfare Office (“Sozialamt“)
To find the relevant Social Welfare Office responsible for you, you can check the "Authority Finder Humborg” (“Behördenfinder”).