Problem: You moved your menu to position-1 in your Protostar template, but it shows up as a vertical menu.

Solution: You need to add a class to the module for the template.css to style your menu into a horizontal menu. Go into module manager for your menu module, click on the Advanced tab. In the Menu Class Suffix box enter this:

Menu Class Suffix   nav-pills

Be sure to put an empty space before the term nav-pills or it will be appended to another class and not work.