HTML + CSS
HTML and CSS are the fundamental languages of code, HTML is the skeleton (or framework) of code and CSS is the dressing on top that provides the aesthetic. These are usually the first coding languages people are taught.
HTML + CSS language course [codecademy]
Intro to HTML/CSS [khanacademy]
HTML and Java Script [khanacademy]
HTML, Java Script and JQuery [khanacademy]