Web development

HTML is the barebones minimum you need just so you know how formatting works. CSS is for the rest of styling and supplementing the HTML formatting to make it look pretty. JS is pretty versatile in the sense that it's generally used for client-side calculations or animations, just to add that extra bit of flair, but it's starting to get used for backend work with Node.

PHP is the most widely used backend for web development in the world. Node is following shortly after. Then, I think R/R and Python. Don't quote me on that, since I don't know how much Django has grown since (a python framework for web development.)

MySQL, MongoDB and MariaDB are the big database management systems.

It only starts to get interesting once you realize that the barebones you used earlier can be parsed as a giant multidimensional array later on. But don't concern yourself with that yet.

This should give you a quick list of technologies you'll need to know. Whether you want to do backend or frontend, you'll need to figure that out yourself, so take a peak, do some reading, do your research, and find out what truly interests you.