I'm building a simple airline reservation system (web app) for a class. I'm trying to find out where to start learning about implementing and integrating a sql database. User's should be able to search for available flights based on destination and departure cities and the like. A good example would be Google Flights. I'd like to access a data base with all of the flight information and display it within tables on the web page. Admins should be able to modify the databases as well.

I've tried to learn about things like Node.js, PHP, and AJAX, but most of the tutorials that I've found have been difficult to understand. Any suggestions would be really appreciated, thanks!