The telc Deutsch B1 certificate proves independent language use and is the usual evidence required for a settlement permit and for many apprenticeships. It tests listening, reading and writing, plus an oral exam taken in pairs.
Berlin has one of the densest concentrations of language schools in Germany, from BAMF-funded integration courses to evening classes for people in work.
There is nothing currently scheduled for telc German B1 in Berlin. The language schools here still take enquiries.