Cascade is a small town - the population is only a little over 1,000 people. People here stop for pedestrians wanting to cross the street, and they expect you to do the same. They're very serious about their speed limits, too (consider yourself warned!). The economy used to be based on logging - it still is partially, but is gradually turning toward recreation and tourism.
Cascade has this old-fashioned kitschy sign for "The Chief" Restaurant, but it also has a modern little drive-through espresso stand across from the Roxy movie theatre (if no one's there when you pull up, just cool your heels for a minute and someone will come out of the building nearby to serve you). The biggest nightlife here, as far as I can tell, is gazing at the millions of stars unobstructed by big city lights.
If you want to go fishing, stop by Tackle Tom's first for the fishing report. They have a board inside telling how the fishing's been at different spots, and the guys who work here are happy to chat about what they've heard. You can buy your Idaho fishing license here and your bait. They're on the main road as you drive through town, on the right at 304 N. Main (aka Highway 55).
In the unlikely event that you arrive when Tackle Tom's is closed, you can also buy a fishing license across the street at Howdy's Gas & Grub (a Shell gas station).