How to Create a Placeholder Menu Button

Go to Pages & Navigation tab in the admin menu. Click on the blue "Add New Page" button in the submenu. 

In the Name field, add what you would like the menu button to say.

For Type, select "Link to File or External Website."

Put "#" in the Link box.

Click on Add Page

This page will appear at the bottom of the box of the right, find it and drag it to the box on the left. 

Make sure to click the green "Save Changes" button when finished.