The episode takes place on Valentine's Day (February). In the same episode Adam joins the tennis team and they are playing tennis in shorts and t-shirts enjoying warm and sunny conditions, green leaves on the trees, etc. February in Pennsylvania would typically be gray, cold, icy or snowy conditions, no leaves on trees, etc...
No business in the 1980s as small as a dying disco would have the money to have a credit card taker that would instantly approve or decline a transaction. Those did not become more common until the 1990s.
Adam says he's never been that close to sports before. However he's previously been shown playing hockey.