Berlin has the largest turkish population outside of instanbul. They have turkish restaurants everywhere and also grocery stores.
The population is ethnically very diverse, though of course, more middle eastern people than latin american ones.
Germans tend to be proper. So, drinking beer on the subway might be frowned upon, but nobody will comment. If you're obnoxious or noisy or otherwise being a jerk, germans will not be friendly to you. If you're polite, they don't care what you look like. If you've got a chip on your shoulder, you may mistake their coldness, which is really professionalism, for judgement, which it isn't.