Can I use html and js to make a new coding language compiler?

Answer 1

Yes you can

Answer 2

JS yeah; HTML is visual and would be of no use itself.

Answer 3

HTML definitely not. JS probably, but it won't be easy since JS itself isn't a compiled language.
You can instead make a transpiler, the most well know example of this is probably CoffeeScript (which produces JavaScript after transpiling).

Google for the differences between transpilers and compilers.