Insure car for the first time

Hello, I am 20 years young and have bought my driver’s license on 26.11.2012. Of course, the joy is there and one of course would like to buy his first car. I compare the insurances for a very long time and have found one now, namely: https://www.wgv-heindelblau.de/portal/en/home/startseite.html There I would pay 220€ quarterly without Kasko, i.e. only motor vehicle liability. Since I want to buy a cheap car (Twingo, Corsa B, etc.) with which I practice the trial period 1.) I would take the insurance start 01.01.2013. But how does the insurance take place? If I say we buy a car in two weeks, and I have chosen the insurance start on 01.01.2013, can I then not drive before 2013?? So that would be really nice if one would explain to me perhaps briefly how the whole goes on with the first car purchase, because I don’t really know me. and before I somehow make myself punishable by what I know.. Thanks already to you