How To Load text domain in wordpress theme?

With this function you take the first step towards making your theme available for translation.

Its best to call this function from within the after_setup_theme() action hook i.e. after the setup, registration,

and initialization actions of your theme have run.

add_action('after_setup_theme', 'my_theme_setup');
function my_theme_setup(){
    load_theme_textdomain('my_theme', get_template_directory() . '/languages');
}

Now add a directory named ‘languages‘ in your theme directory.

You can learn more about load_theme_textdomain() function on the WordPress codex page.