Am new in this city and I don't have any friends. I want to know where I should go to met new people . And maybe learning from them the language a little bit .
I don't know what to do really !
in my view its the best to join sportsclubs
You can look in facebook for groups like "Neu in (city)" or to speak german search for "Tandem (city)" to find people who are looking for a tandem partner.
You can also check on couchsurfing.org for local events, they usually have weekly meetups in bigger cities...
there is this website called meetup.com where you can find local events as well
If you tell us where you live we can give you more advice =)