The people in Germany seem to be quite helpful towards English speaking people. Many Germans know some English and if you want to increase your chance of meeting someone who speaks English I recommend approaching someone under the age of 30. (English is a mandatory second language in German schools, therefore most young people know some English).
The Germans can be an enigmatic bunch. Conservative and rule-abiding on one hand and yet relaxed enough to let it all hang out at numerous mixed, naked saunas. But even in the sauna - rules are rules.
You can use your international cellular phone rental to get closer to the people of Germany.