Add functionality to a WordPress site

An existing WordPress site has different pages with different functionality. On the main page, you need to place a short catalog of top products with the ability to go to an extended catalog (products have already been created, the catalog is used on other pages of the site). I also want to change some elements of the site to reduce the height of the site in
including in connection with the addition of a catalog. I want to discuss the details of how best to do all this with the selected performer.