All our themes support custom menu features that comes in the new version of WordPress which enables a user to create custom navigation menu in place of a theme’s default menu.
To organize your menu, simply navigate to
Appearance → Menus then click the + button to add new custom menu and hit Save Menu button. Next is add menu items such as pages, posts, categories or even custom links that you want to appear in navigation section of the theme then you may organize the order or setting sub-menus by drag and drop or indenting menu items. Lastly, assign the created menu to theme locations and hit Save button.
If in case you’re using a theme of ours that is capable of adding subtitle or tagline to menu items such as SimplyBiz Theme where it has a menu item "About" and subtitle or tagline of "Get to know us" then you can achieve that by clicking Screen Options and check signing Description option. Next is to edit menu items then put the desired subtitle or tagline at the description box and finally hit the Save Menu button.