Questions R19 bj 1995

Hello you loved ones. I bought a nice R19 a week ago. and have some questions 1. at the start, he needs about 2-3sec until he is on then the speed is almost 2000 and goes very slowly down is the normal 2. the servo goes pretty bad (or I’m spoiled ) 🙂 3. is the normal that I only come 550km with full tank. or can you do something there ?! the car has down the 140000km and new bellung was made by the previous owner as well as the brakes, new Oil and filter. can one possibly tell me what else I have to do to keep the car fit so that I have my fun for a long time. (is my first own car) and want to do everything right.