Short-term identification marks and comprehensive

Hello together, finally I ordered my Skoda Octavia from an EU car dealer. In 4 months (I calculate with 6) I should be able to pick it up at the other end of Germany (simple route 850 KM). I informed myself a little bit and learned that I need a so-called short-term identification mark for the journey home. A few questions: 1. Where do I get it? Insurance or registration office? 2. How expensive is it? 3. I absolutely need a comprehensive insurance (sch Is this common with a short-term registration mark? 4. What documents do I need? And how do I go on afterwards? 5. I have to take out the insurance with the COC paper first for insurance, normally and then to the registration office, right? 6. Does the insurance not require the vehicle certificate Part I and 2 or is the COC paper sufficient to replace it? Hope someone can help me further. Thanks and LG sc hwokels