On my way, but where do I begin?

Hey folks,So I've started the process of getting my bike license (UK), already completed my CBT and booked my theory, DAS should follow in January.I want a project bike, something I can tear down, learn about and build on, and I've been looking at various bikes, Honda CB, BMW R100, Yamaha RD for example.But being a complete bike novice, I don't know what to look for in a bike when it comes to buying 2nd hand.Any help and advice would be greatly appreciated.What were your first bikes? via /r/CafeRacers https://www.reddit.com/r/CafeRacers/comments/a747qy/on_my_way_but_where_do_i_begin/?utm_source=ifttt