HTML- What does it do?
HTML consists of tags that are saved as a html file. These are viewed in Browsers which read and translate the tags into a web page. These files are created in a text-editor and can be formatted additionally with other web developing tools, languages, and frameworks.
You should spend at least a couple of weeks learning HTML
Below is a listing of places to learn HTML adequately
Where to Learn HTML
I really like Khan Academy as a starting point. Their HTML/CSS course is great to start out with
But try out as many of these as you can, we are all different and all of these sites can teach you something