A friend of mine asked me to make a few minor modifications on his website (change Titles on each page, add a clickable mobile link for phone number, add business hours in the footer, add scrolling menu in nav bar...) I am comfortable in HTML and CSS but not that much in Php. I can't seem to find the HTML files for each page. I read that it should be php files like index.php but, how can i make html correction to those? I have access to themes and files via Bitbucket but I am a little stuck here. Can someone please help me? Thanks Drey
WordPress is not HTML. It's PHP-based templates that build the HTML pages.
You need more than just a quick answer. You need to learn about the entire process WordPress uses to build pages.
Perhaps one place is to start here to figure out how WP works: https://codex.wordpress.org/New_To_WordPress_-_Where_to_Start . And if you are not comfortable with PHP, then you need to get some basics about how it works so you will understand the code behind the WP templates. Perhaps start here to learn about PHP: https://www.w3schools.com/pHP/default.asp .
This is not going to be a quick process. It will take some time and effort on your part. But you might have fun doing it.