Despite having a CS degree I actually never took a web development course, as my small liberal arts college didn't have one. So, I taught myself everything I know about it using free resources off the Internet. If I did it, so can you! B)
When I was younger I tried to learn Javascript off of w3schools and failed. Now that I am more learned, I think I know why it doesn't really work. It does have a lot of information which makes it good as a reference, but that can be overwhelming when you're just starting. You can learn about each component of a particular technology individually, but not much about how they work together in the context of an actual website. For HTML and CSS this can kinda work out OK since they're not actual programming languages, and you can work on pieces of them in isolation and stick them together at the end without problems most of the time. But, if you want to make anything halfway useful in Javascript (or any other programming language) you need to know how to break down your problem into steps a computer can carry out, have an idea of how to implement each step in code, and fit them all together correctly at the end. Just knowing how to write a for loop or an if statement out of context is not going to get you very far with that.
What I credit with actually teaching me programming are Khan Academy's free courses. I think these are more effective since they are more focused and hands-on: you do a lot of little challenges and projects that build on what you've already learned. The most applicable ones for making a Neocities site will be the HTML/CSS one and then the HTML/JS one, but I encourage you to take a look at the rest too. I had a lot of fun with the Advanced JS courses in games and simulations! Then once you've learned the basics, if you ever forget a piece of syntax you can look it up quickly on w3schools.
A more advanced resource would be Mozilla Developer Network, which has both very in-depth documentation for web development technologies and some pretty helpful tutorials. For responsive design and more advanced CSS stuff I like Kevin Powell's YouTube channel.
With all that said, it can be easy to get caught up trying to find the perfect tutorial or reading through resources. So I think it's most important to just pick one and go for it! As long as you're making stuff you'll be learning, so try not to worry about making something good right off the bat or not improving fast enough (easier said than done I admit)... which honestly goes for learning any skill.
Also important: just keep at it! Programming can be its own special breed of frustrating especially when you're just starting, and some of the concepts might take some time to fully click. But, the feeling of finally figuring it out and seeing your program actually work is 1000% worth it IMO. If you feel really stuck step away from the computer for a bit and let the problem marinate in the back of your brain, maybe even come back to it the next day. This method has come through for me numerous times, usually when I sit back down and look at my code again I figure out the solution fairly quickly.
So.. go make something! Make something super small to start off with (Hello World)! Make something bad/stupid/silly on purpose! Good luck and have fun! BD