Changes for web PHP

Carried out by a Web programmer progarm as external, I need to make changes and change the Configuration ## Deliverables made are: installation of 2 new sections in the menu, a video gallery and a calendar of monthly events setting up a script to upload multiple photos (already done but need to configure) The whole site is in php and any change is very difficult for me, so I need help tocustomizable. to be made are: installation of 2 new sections in the menu, a video gallery and a calendar of monthly events setting up a script to upload multiple photos (already done but need to configure) The whole site is in php and any change is very difficult for me, so I need help tocustomizable.