Unless you are quite fluent in German it is not so easy to practice it. Many people are very fluent in English. And if not, someone will often fetch someone who is to deal with you. Only if they really need to will anyone persist in trying to communicate in German with you.
However, there are options – language exchange in one of its forms.
Tandem – you can search for different sites that connect people who wish to language exchange:
and others. I was not successful with these. Probably some people are.
Or you can attend exchange activities such as:
Monday night from 7pm:
Cafe Buchhandlung, Tucholskystrasse 32 Near Oranienburgerstrasse S-Bahn Station.
Tuesday afternoon 4pm – 8pm
Artists Meeting Point (AMP), Kreuzbergstrasse 71
This is about 10 minutes walk from Mehringdamm U-Bahn Station (U7.
Tuesday evening 8pm –
Polyglot Club, Kant Cafe, Kantstrasse 135
Wednesday 6.30pm –
Cafe Caras, Potsdamer Platz – Leipziger Platz 1.
S & U-Bahn is Potsdamer Platz
These are all ones I have attended, and all are good. There are plenty more, you just have to search for them. And perhaps you can find someone there to regularly practice with, too.