Insurance questions

Hellas I once again had today the post of an insurance offer in the letterbox. while asking the question since when I have my FS, is there the B or the A fs meant ? also make me drive the offer on 60% sf. can that be true ? had never registered a vehicle on my name, and I am not yet 30. is that perhaps a lock offer or would the 60% bind at conclusion of contract or at registration of the vehicle ? as always best thanks patrick