WP Beginner has a great explanation on a few ways you can accomplish this. Click here to view their article.
They more or less explain the 2 options that you have. You could install a plugin called 'Polylang' which allows you to manually add translations for categories, pages, taxonomies, posts, URLs... everything. You are then given a language switch that you can plop on you site where you find it best suited.
The second option that requires less manual labor is to add Google Translate to your site. This translates the entire site and similarly gives you a customizable language switcher to be displayed and use anywhere on your site.