I did a bit of programming a few years back on HtMl but with all the new stuff out now should I really go back to re-learning Html - I have to start learning be

I did a bit of programming a few years back on HtMl but with all the new stuff out now should I really go back to re-learning Html - I have to start learning before I start hacking - I have created 2 freebie websites - but I didn't need my own code - ok so I copied some radio station free code and put it on my crappy site - but now I want to write it all myself just the best way to start?