Welcome to Nico & the 240 club. I'm very surprised at how well kept your 240 is after 250k miles, very impressive.Start off by reading this thread
zerothread/183490and do some wiki research on your car. You can learn a lot if you take the time to read.
Also take the time to read through other people's build threads. You can learn a lot by seeing how other people work on these cars, what they do, steps they take etc. When you see people talking about parts you don't know about, google images is your friend.
Yes, searching requires more effort than posting your questions on a forum and waiting for people to answer you - but you'll be ridiculed less and learn more if you take initiative and make proper use of the brilliant search function.
Enjoy your stay