Get ready to buy a car!

Hello, I will soon be looking for my first car. It will be either a Fiesta Mk4, Corsa B or a Micra K11. Now I wonder how I should best proceed in the search! Which important criteria should I look for? Which factors (KM stand, TÜV, price, inspection, repertures …) have top priority? So it is more important that the TÜV is new or that the timing belt has been changed, etc.? How many cars come into the final selection? Which Fra So these are a lot of questions now, but I hope you can answer them bit by bit I’m a little lost in the car forest. Lg