After installing Oxygen make sure your license key has been added at Oxygen › License in your WordPress dashboard.
View and add components by opening a page or view in the Oxygen Builder. Click '+ Add' and select 'Design Sets'.
Click Pages to view all of the pages from the demos shown above. Page headers and footers are stored in the Reusable page.
Now you have the pages and components you need create your site. Customize the components or create your own from scratch.