Ideas for low level puzzles?

I'm an English instructor in Argentina, and I'm planning a DnD short campaign for my students (teenagers with a decent command of the languages, B1 if you want to know). I already have the main idea laid out (a village riddled by goblins where the mayor is in cahoots with them). But these goblins are rather stupid. I want to add some low level puzzles that involve comedy-like situations with the goblins. Which ones do you suggest.

More info: the goblins HQ is a complex of caves some 2 days walking distance away.