Loading different page assets dynamically

First of all, let me put it out that i am a first time web developer. I am not entirely sure how to describe my problem so please bear with me. I will try my best to properly articulate it. So, here we go.

I am developing a website using PHP and MySQL as backend and XAMPP as the server. I am currently learning from a tutorial where the instructor creates a CMS which has only one page design that he reuses by changing the body in each of them. The website that i am trying to create has three different page styling. All the three pages have their respective headers, bodies and footers in a single file each. (I understand that its good practice to have header and footer in separate files. I tried that but due to some reason the CSS for the files didn't work. Therefore i am going with the header+body+footer in one file until i can resolve the issue).

Lets call the three pages

1. homepage
2. search_results_page
3. profile_page

I want the search_results_page to render after a successful database search. I want the profile_page to render after one of the search results is clicked.

Bear in mind all the pages have different front end styles. How would i go about linking these pages? Thank you for your patience.