Character mistake: At one point Cory is telling Shawn about how he can't protect Topanga and they've only been married for one week. But they spent their wedding night in jail, 12 days on their honeymoon and 1 night in their new apartment. So actually the couple have been married for 2 weeks.
Factual error: When Cory and Topanga first enter their new couples dorm, they discover it to be a dump. The entire dorm is filthy, cabinets are falling apart, there are large bugs crawling on the floor, and there is no clean running water. Student housing laws would require the university to restore the dorm to liveable conditions before any student could move in. If the health department saw the conditions of the room, the university would undoubtedly be fined for failing to take corrective action. (00:07:45 - 00:10:36)
Chosen answer: In the present day, with the United States abiding by more stricter school health laws, for the most part this wouldn't be in school cafeterias as many cannot even have carbonated beverage machines now. However, in the 90s when the show takes place, it wasn't unheard of for there to be coffee machines in the cafeteria of small schools where the teachers eat with the students as we see them do often in the show. The idea being that the cafeteria was small enough so a teacher or hall monitor could catch a student before they could drink the coffee.