Following are the steps for creating a SharePoint 2013 webpart page.
1) Go to the site and select Page->View All Pages. Alternatively, you can create your own library and select View All Pages option.
2) Click on New Document button and select Web Part Page option.
3) Provide a name for your page and select the suitable layout template. While selecting the template, a layout preview will be displayed on the left. At this point you can also change the document library to which this page will be saved. Click on Create button to complete the creation of the webpart page.
4) Go to the document library and the newly created webpart page will be available there.