I recently took a few trains in China. I have had nothing to do with the purchasing side of things, that's always been handled by the relatives we are staying with. Note that I speak only a handful of Chinese words and read none.
At the station: Only once was it not completely clear where we were supposed to go and that was a question of what area to go to--had I been alone it would have been easy enough to resolve by showing one of the station people the ticket and looking puzzled--I'm sure they would have pointed in the right direction.
Beyond that it's basically like an airport--you have a train number on the ticket, the train numbers are listed on the departure board along with track numbers. A train is "boarding" (you can go to the right platform--if you're at an intermediate stop the train might not be there yet) when it's green. I actually did better than my Chinese-speaking companions at this, for some reason they were looking at a secondary board with only three trains on it--our train was the fourth on the big board when I double-checked as it was getting close to train time. I'm not sure we would have made it had I not noticed it, as it was my wife was the very last person getting on the train. (This was an intermediate station and we had a long walk to our car. While I didn't time that stop I timed the others on that leg, the shortest was 4 minutes, the longest was 7.)
Every sign of importance was easy to figure out. Generally there were symbols that made it clear even if you couldn't understand them, and there was enough English to get by without the symbols. Announcements on the train (but not the station) were done in Chinese/English, as well as the scrolling information displayed in the train car. I have yet to see anything in China on tracks where the signs weren't adequate for an English speaker to travel (I've never been involved in purchasing), although I have seen buses that weren't so clear.
Expect security checks at every station, sometimes even two checks. Sometimes it's just baggage x-ray (and I've yet to see security want to look in anyone's bag), sometimes there's also a WTMD backed up by wands if it rings--whatever the wand beeps on generally gets a pat-down, although they normally ID by touch and you don't have to show the metal. One screener wanted me to drink a little bit from a water bottle in my pocket (and had enough English to say this), everyone else just grabbed it and gave a bit of a squeeze, enough to get that characteristic crinkle they make, and went on. Note that this is not TSA-level security, I can't think of anything I would reasonably want to carry as a tourist that would be prohibited.
China has gotten a bit nuts with the metal detectors recently--the craziest example was at some tourist thing, I forget what now. There were detectors that everyone had to walk though but absolutely zero follow-up when they rang, as they did for everyone (there was no x-ray for your bags, everyone was carrying their stuff through them.)