The Glossop Cafeteria, Victoria Steet, does very cheap, mainstream English food. It gets quite busy though. You can get an absolutely massive full English breakfast, for example. My favourite pub is the Star, at the back of the railway station. Good beer, but I note that they now only open in the evenings during the week, and only at 13:00 even at weekends.
Unless you're into walking, there's not a right lot to do in Glossop (IMO). However, there are quite a few reasonable pubs and restaurants, and it may be worth half an hour on Tripadvisor to see what suits best.