Customize the Jumbo Theme on a React Website

I have a website that is using the Jumbo theme and I need it customized a little bit: -add text and logo to the home page of the domain, -edit the admin page to delete unused theme components, -edit user page to delete unused theme components, -turn on the "settings" option for the admin page so admin can update email and password -turn on the "settings" option for the user page so user can update email and password -prepare a written guide on how/where changes were made so future non-coder can edit the theme