Ask HN: Web programming... Where to start?

Let me begin begin by introducing myself I'm 17 and I love thinking about startups and the web (This is my most notable accomplishment in this field: foodo.me). But it's hard to implement projects you come up with if you don't know a little bit of how to code. So I've decided I need to learn to program for the web. Previously I took Stanford's intro to CS class via their online program (http://see.stanford.edu/see/courseinfo.aspx?coll=824a47e1-135f-4508-a5aa-866adcae1111) and learned a little bit of Java through that. However, I have had trouble continuing and figuring out where to go next. I've dabbled in Python(using the google course), PHP(briefly), Rails(using Michael Hartl's Rails tutorial) and even tried doing GAE in Java. But I keep failing miserably. I need advice on a way for a total noob to get started with web programming. I know people who can answer questions about most languages so that's not a factor. I just need solid advice and a jumping off point.