For a user trying to update their site without knowing anything about WordPress, the admin area can get somewhat daunting. The options and places to change and update items can seem rather tricky. Usually though, if you are attempting to add a link to your menu or update an existing area in a header, footer, or sidebar, the first places to check are the menu and widget areas under the Appearance menu in the Admin back end.
Menus allow you to add various types of items to the different menus in the system. Typically the main menu navigation will be what you’re looking for here.
Widgets are contained in various places on your site and different page templates may have different widget areas. These will usually be listed with pretty self-explanatory names in the Appearance -> Widgets area. Widgets can be links or many other things such as posts, or extensions added by plugins you can install.
In any case, it’s good to know about these areas of your site if you are interested in DIY WordPress site updates.