HTML isn't really a programming language.  It's a markup language - it holds and somewhat formats text and graphics.  If you want to do programming in an HTML environment, you want Javascript.  If you really want to format text and graphics well, on the other hand, you want CSS.  CSS (Cascading Style Sheets) is taking over the formatting work from HTML, so HTML more or less just holds text and some data.
Javascript doesn't have an awful lot going for it as a first language, except that you don't need any extra software to work with it.  Programming languages are all alike in many ways, so once you learn one language it's easy to pick up more.
On the other hand, language APIs are almost all different.  An API (Application Procedural Interface) is a bunch of pre-made program bits (procedures) that let your program interact with more than just its own math and maybe printing text on the screen.  The  DOM (Document Object Model) is sort of the API for Javascript to interact with HTML and CSS.  But different browsers implement the DOM differently, particularly Internet Explorer vs. Everyone Else.  There are APIs that will interact with each DOM properly for you, and this seems to be the direction Javascript is going in these days.  In particular, JQuery seems popular.
To summarize:
HTML: Holds data, can format text and pictures, but that's becoming an obsolete use for it.  It's not a programming language.
CSS: The new way of formatting text and pictures, necessary for a "modern" web page.  Also not a programming language.
Javascript: An OK, but not great, programming language.
DOM: One way for Javascript to create/modify HTML and CSS.
JQuery: The current/likely future way for Javascript to create/modify HTML and CSS.
Do you still want to learn HTML?  Wouldn't you rather just learn Python and TkInter instead? 
