Liability damage – What can I/can I do?

Hello together, I would have a few general questions about the procedure, because it is my first accident and I could not find any or repeatable answers to my questions so far. The following is passed: I stopped before a roundabout, in front of me still three to four vehicles, the backman braked too late and drove me up. The fault is therefore clearly with the accident opponent. Since his vehicle is a company car, the whole was also put up by the police More information on how to get here and pictures can already be found here: http://www.motor-talk.de/…/…-accident-collectread-t4692510.html?… So and now you can read all over the net what you are entitled to as a injured person: free choice of expert, lawyer, etc. Also I have read that as a injured person you do not have to go into advance and attorney and expert directly calculate this with the insurance. But what does not stand anywhere, what do I need to do with it? now wait until the gengerische Versicherung registers with me? Should I report the Sachden itself there? For this you will find repeated statements. Can I go to an expert now or do I have to wait until I have heard something about the opposing insurance?