What that mean?
Wir können “siezen” (formell sprechen) und “duzen” (informell sprechen).
You can “duzen” with friends und good acquantances: Was kannst du mir davon erzählen?
You should “siezen” with old people and with your chief: Entschuldigen Sie bitte…
If you are a beginner I would recommend to start with the first course of this series for absolute beginners: “Ab jetzt lerne ich Deutsch! German now!”: Login - LingQ
Lots of lessons come with a translation into English.
You should start with the first lesson of this course: Login - LingQ
“Ab jetzt lerne ich Deutsch! Privat!” is the second course of my beginner courses. These courses let you improve gradually.
On my blog you’ll get some help too:
Beginner: Helpful to start learning German (Beginner in English): http://learninggerman.verasblogs.com/beginner-in-english
Good luck with your German!