zShop uses the zMenu API, so all zMenu configuration elements are available here. It is advisable to also read the zMenu documentation.
zMenu works with a button system. zShop will add several new button types to create a Shop plugin. You can find all the information about zMenu buttons here, and zShop here.
In the plugin default configuration, you will have a /shop command and a /rank command.
/shop command will open a complete shop ready to use.
/rank command will open an inventory example that can be created with the ITEM_CONFIRM button.