Could you provide temporary wp-admin access?
1) Do you mean the default Shop page?
To use the default pagination, you need to disable WooCommerce Infinite Scroll and Ajax Pagination plugin. If you want to have Infinite Scroll, Load More Button or Ajax Pagination for products, set correct settings for the plugin – https://xstore.helpscoutdocs.com/article/65-woocommerce-infinite-scroll-and-ajax-pagination-settings
2) XStore theme does not have the search by tags. If you want to get this option I would recommend you to look for additional plugin for the advanced search or submit additional customization request to WPKraken team.
Additional customization in files is beyond our basic support scope.