Hello,
1. Theme Options > Import / Export > Dummy content > Import of the additional pages > http://prntscr.com/kndzzr
Then edit menu in Appearance > Menus.
2. If you use Double menu header type, you need to create 2 menus http://prntscr.com/kne2g8 + http://prntscr.com/kne2oe
Feel free to ask if you have any other questions.
Regards