An American will arrive in Germany, and eventually come to discover the all-important bahnhof (the train station). So, there's some advice here.
First, the sizes relate to the town....so Frankfurt will have a monster-sized bahnhof with pubs, restaurants, and various business operations. Some small town in the middle of nowhere....will have a pub....if they are truly lucky. Some of the more interesting bahnhofs that you might stumble across: Frankfurt, Wiesbaden, Munich, and Stuttgart.
Second, there's typically parking available but you always pay for what you get. My advice is to avoid these circumstances unless its really necessary. Most have bus service or subway service into the bahnhof.....park on the outskirts of town using a free parking situation....and ride into the station.
Third, before the 1980s....there were actual people in the ticket booths at every single station in Germany. You could ask stupid questions and get advice (half of them actually English at the time). Things have changed. So if you live in a German town of ten thousand folks.....and you have a bahnhof....don't expect a live guy to be there to sell you a ticket. It'll be a machine. It will offer a English language option, which is helpful. You can also go online, and view your travel options via bahn.de.
Fourth, if you do get stuck at a bahnhof for several hours....there tends to be a pub within the building. It won't be fancy or cheap, but you can get a drink or two while waiting. I would strongly advise you to watch your consumption and don't miss your connection two hours later.
Fifth, food is not something you ought to be thinking about at a bahnhof. Bakery goods might be acceptable....but after that, don't order any real food items. It'll be a lousy meal and probably twice what you ought to pay.
Sixth, crime within bahnhof is typically not an issue. You are probably at one of the safer places in any city. Now, with that said.....if you are in a metropolitan city and outside the bahnhof.....you are in a zone where you might want to avoid. Cities like Frankfurt have a drug culture within five minutes of the bahnhof, and people get stupid around these areas.
Seventh, bahnhofs tend to be historical in nature. So when you stand there....take a moment to look at the construction, the ceilings, and the windows. The Wiesbaden bahnhof is a building that you could spend half a day walking around the interior and exterior...discovering things that most people just overlook.
Eighth, most bahnhofs are open by 5AM, and close sometime around midnight (depending on the last train). There are a handful of bahnhofs that are open twenty-four hours a day.
Ninth, for a day-long excursion....you tend to discover that as you venture out into German cities....the bahnhof is this central location where you can base all your orientation onto, and return in the late afternoon to travel back to your original spot. You can rattle off the top 200 cities in Germany....and the bahnhof of each is within mile of the center of town in almost every single case. Most sizeable bahnhofs will have a book shop inside, with maps on sale....so if you were hoping for a map of the town....they've got it (never less than five Euro or $7 though).
Tenth, there are certain occasions that you might want to avoid bahnhofs....like when a major soccer club is visiting your town for a game. Yes, there are fairly rowdy folks who show up and for an hour upon arrival and probably two hours upon leaving that evening....it's not the place that you want to hang out or be around. If you know of a major demonstration coming for Saturday....that might be a good reason to avoid the bahnhof because of incoming crowds. But the other 350-odd days a year....ought to be ok, and acceptable.