Trade is the lifeblood of nations and peoples, and this book presents a temporary trading settlement that springs up and opens for business with just two core rules: stay out of trouble and don't close your purse strings too tightly. Sounds ideal for weary adventurers wanting to offload loot and stock up on supplies...
The DM's background tells you more. The Azulites are often derided as gypsies or vagabonds, but see themselves as a 'travelling village'. The reasons why are laid out for you. Following this is a description of the standard layout used by the travelling village and details of some of the main inhabitants and the goods and services that they offer. These include an illusionist who puts on spectacular entertainments with the help of three acrobat brothers and the local bard, the bard himself, and an elf who is an exceptional cook - she'd probably have a couple of Michelin stars if such were awarded on your world!
Whilst this isn't an adventure per se, more of a setting, several adventure hooks are provided if you want more than just having your party encounter the travelling village and wandering about it for a pleasant evening, trading and being entertained. You could run several through a very busy evening at the encampment, or a different one each time the party goes there - assuming that both party and village are travelling in the same area for a while - or even build one into a larger plotline as you see fit. Alternatively, you might want to latch on to the quarreling kingdoms that caused the village to start travelling in the first place and build a whole campaign - or at least several adventures - around that.
With a new magic item and a new spell to be found here, it makes Azul a delightful place to visit, be it for an evening's rest and entertainment, to stock up on supplies and sell loot, or even a chance encounter on the road. As for where to put it in your campaign world: well, as they wander it could be just about anywhere... they may have strayed far from those two squabbling kingdoms by now.