I would like to know how to create a new (main) page, with new categories to select (as if it were the main home page), for example in the (COLCHONES ) section of my home page.
my page is under construction
Sorry, but your request is a bit unclear for me, please describe the desired result in more detail.
Go to Pages > Add new, add the desired content, then you can set this page as Home via Dashboard > Settings > Reading >
Your homepage displays.