Adding Dropdown Menu

I am trying to add a drop down menu to my site but I can’t get it to work right. I installed the Dropdown Menu Widget plugin by Matt Say, but when I go to the widget page to add it the only options I have are the side bars and footers. I thought there was a way to change the regular menu to a dropdown menu. I need to be able to add sub pages to the pages listed in the navigation bar. I am using Figero by InkThemes as my theme. Any help at all would be greatly appreciated!