A little JavaScript might help. It’s helpful to have the background because it makes it easier to truly understand things like conditionals, variable assignment, variable scope… But it’s also a detriment, because there are a lot of significant ways in which CS differs from a “real”, fully fledged programming language. Most of these are things that are elided to make it more usable for writers, but for a programmer it can be frustrating. There are things I expect to be able to do that are illegal in CS.
I mean, if you have HTML background, learning a little JavaScript can only do you good, IMO. I mostly use W3C Schools as a reference source, but they have beginners’ JS tutorials, also. There are other sources, too, of course, but that’s the first that sprang to mind.