Step 1 : From dashboard, on the left menu, go to: Appearance > Menus
Step 2 : On the left menu, click Pages tab.
Step 3 : Then, click any Pages checkbox and click Add to Menu button to add page into menus.

Step 4 : Or if you want to add the specific pages into the menu, click Custom Links tab, paste the URL link and enter Link Text.

Step 5 : For example, click HOME menu tab, to edit the Navigation label.
Step 6 : The arrangement of the menu can be organise by just drag up and down the menu tab.
Step 7 : Lastly, click Save Menu.