Add plugin to servers plugin folder and run the server to generate config files, config.yml will store the uuid and balances of players, shopconfig.yml will store the config for the shop. There is a default shop, but it is most likely that you will want to make your own. Each shop page will have its own key in the yml file, and the first page on the yml will be the one opened by the /shop command. How to customize is shown in the yml.