How to display / filter new products?

To enable the New Product Page, navigate to Customizing > Shop > Custom Archives > New Products and chose the option presented below:

The actual New Product Page can be viewed in the Mega Button:

And Shop Sidebar area:

How to show products added in the past x days  ?

You can set to display products that were added in the past 60 days or lower, navigate to Customizing > Shop > Custom Archives > New Products > Show products added in the past x days and use the controller to select from what day.