How to I change the word "page" in my url

Not sure this is still valid but you may want to look at this plugin in the repository.

https://www.ads-software.com/plugins/custom-pagination-permalinks/

Good luck with your project.

Hello,
Please add the following code to your functions.php file:

function wa_rewrite_rules() {
    global $wp_rewrite;
    $wp_rewrite->pagination_base    = 'sida';
}
add_action('init', 'wa_rewrite_rules');

After adding the above code, visit the Permalink options page, and save the changes a few times.

Dashboard >> Settings >> Permalink