The shop configuration can be found under the settings package, you'll find everything you need to manage the pacakge.
The payments package is required to use Shop and it needs to be configured, otherwise, no public views will be working as there would be no way of paying.
The solution then, is to configure the payments package and then configure the shop package.
Make sure you edit the public shop views after publishing them, so you can adapt the design for it.
the default path after the publish is: