Mobile: How to indicate presence of landscape mode and expandable elements?

Problem:

My company has a desktop website to display reports, and now also a mobile website. The reports there have only 3 columns in portrait mode to keep it clean, but show extra columns when you switch to landscape mode. However, when I track how the users use the site, literally nobody uses the landscape mode, but rather go to the desktop site when they can't find the details they want.

Also the rows expand when you click on them to show all the details, but nobody seems to have found it so far...

Question(s):

• How to indicate landscape mode is available for more details?
• How to indicate rows can expand upon tap?

Currently I see no other solution than showing a one-time popup, but I'm sure there must be other, more elegant ways!