The main station in Frankfurt is large, clear, and convenient. Great with food. That's just that a real ghetto has formed around in recent years - it's better not to walk at night
The train station is like a train station. It is very difficult to navigate. There is no normal information in English. If you are German, then most likely everything will be OK.
Everything is intuitive. We bought tickets without any problems. There is a place to eat and drink good German beer) well, the architecture of the station is very beautiful