how to delete blank pages

To manually remove pages use TOOLS - ORGANIZE PAGES then click on the blank page to select it followed by clicking on the TRASH CAN ICON in the sub-menu bar (this works from Adobe Acrobat DC).

You can also use the EXTRACT menu selection as well as doing other page organization tasks.

To remove them while you are scanning them varies depending on the software for your scanner.  See the documentation for your scanner to see if it is supported (sometimes it is just a checkbox setting).

Manually? Just like you delete any other pages, via Tools - Pages - Delete.

If you want to do it automatically that's much more complicated...