Salam Mohammad,

          I think most common phrases are like in any language. You can easily search them online. However i'd like to point out what most language learners seem to overlook. To practice it is of critical importance. You need to speak that and get yourself understood over and over again. So try to find a language tandem partner, a teacher or just German friends until you are fluent enough. I wish you goodluck with your endeavors :)

Well you can use this youtube channel to help: https://www.youtube.com/playlist?list=PLk1fjOl39-50vwsRJkrKWkmIitlFqTink

You can find common German phrases here:

http://ielanguages.com/German1.html

http://ielanguages.com/germanphrases.html

There are also audio files, but the speaker doesn't seem to be a German native speaker. Sometimes the pronunciation is a bit off.

Here are also a lot of phrases: http://www.fluentu.com/german/blog/common-useful-german-travel-phrases-vocabulary-words/

Just google "basic German phrases" and you will get a lot of hits.

Well i think you need to learn greeting at first ..

Si you Caan say " guten tag , ich bin ..  ( dein name ) , ich bin ( dein jahr ) . '" 

Dank sehr ! =  Thanks