Your ERP5 instance is now ready, but it has only generic core libraries. This core can be extended through different business templates for different purposes.
This can be done manually using My Favorites > Manage Business Templates, installing individual business templates that provides your ERP5 instance with utilities that you need.
But Wendelin uses many different business templates and that would be a lot of work, so configurator is provided to make that work for you and install all the business templates that are needed for Wendelin.
For that click on My Favorites at the top left corner of the page and choose Configure your Site.