After installing the Aimeos package, you should clear the Flow cache files if your application runs in production context. Otherwise, you won't see any shop pages. In development context, the caches are updated automatically.
FLOW_CONTEXT=Production ./flow flow:cache:flush
FLOW_CONTEXT=Production ./flow cache:warmup
Then, you should be able to call the catalog list page in your browser using:
http://<your web root>/shop/list
The administration interface is protected by a policy that allows only editors to access its URL. Therefore, you have to setup some kind of authentication and a user with the editor role first. Afterwards, you will be able to call the URL for the administration interface:
http://<your web root>/shop/admin