It's good to have a strong base of knowledge of HTML/CSS and javascript for web programming, especially javascript, because that's not just used for manipulating the user interface, but also to communicate with the server. However, most of the work with HTML and CSS is layout and design, it's meticulous work and requires a different skill set.

I've done the w3schools tutorials. They're quick and easy. You'll be up and running pretty quickly. My opinion is that it's best to choose to concentrate on which of 3 main areas of web work you like best: Design, Frontend or Backend.

Design is mostly producing pdf files for the web pages or it could include an html/css/js template since there are apps to do that.

Frontend is working within the design (and/or building the pages to match the pdf files) to hook it up to the backend - like enabling forms, error reporting and managing data displays.

Backend is working on the database and and the php functions used to build dynamic webpages, handling user sessions, form processing, etc.

Another option is wordpress, and that's a whole other world which can be quite lucrative. I don't have much experience with it. My overall opinion of it is that it's not a secure platform, and it's a blogging framework that has been turned into a behemoth of a code base that tries (and largely succeeds) at doing everything you could ever want.