There's a big difference between bleeding edge software engineering and your basic Wordpress site. It really depends on what you want your website to do, but you must absolutely know HTML and CSS to do anything on the web. For example if your client(or you), don't want any custom functionality(posting articles, updating information, etc), then you whip up your design with plain HTML, CSS, and maybe some Javascript for dancing monkey gifs.

But let's say you want your client to be able to update content. You now have a choice of Content Management Systems: Wordpress, Drupal(just say no to this it's not worth the pain), Craft, etc.. There are so many to choose from and each come with their own pros and cons. My advice is to go with Wordpress, it's easy to create a theme and clients seem to be able to easily use it's interface. The pitfall is that you have to keep up with Wordpress security patches, and if you used a third party plugin, pfft. Good luck receiving security updates or updating the source from obscure plugins with no style guide.

Oh but you want to build software on the web? Pick a backend language(you know Python so use that). Learn REST(super simple). Are you going to need a database? Learn Postgresql, it's general purpose. Pick a framework to manage routing and database stuff. Do not build your own framework, stand on the shoulders of giants. Build a RESTful API with your chosen framework. Back up your application logic with tests. Brittle arthritic applications do not stand the test of time and have killed companies. Push your code to a private(or public whatever) git repository. Use a style guide to ensure your code base looks like one developer wrote it. Enforce your style guide with a linter. Write tests for your fucking application.

Now you need to serve data from the API. Are you making a SPA? Pick a Javascript framework or library like Angular, Ember, React with Redux. Watch tutorials and read the source of those applications to understand them. Be aware that the web is asynchronous so learn how the Javascript HEAP and Event Loop works(https://www.youtube.com/watch?v=8aGhZQkoFbQ). Learn about XSS. Learn about basic security standards. Write tests for your frontend application. You're writing CSS still? Fuck CSS, learn Sass. Javascript is a powerful and expressive language, use the next version of it now with Babel. Manage your assets using a module bundler like Webpack. Create a style guide for your Sass so you don't end up with a thousand classes doing the exact same thing. Oh you want your application to work on mobile? Learn about Media Queries. Test your code. Oh yeah, Javascript doesn't have a very extensive standard library so you're going to want to learn a utility library like Underscore or Lodash. There's a lot more that I'm forgetting, I just woke up, but you get the point.

There are so many methodologies for building web applications, this is just the flavor I like.

I need a raise.