I suggest you learn SEO and PHP.
SEO is simple, create websites, put content on them, learn what monetization means and how to do it and build links.
With PHP you'll be able to create web applications and complex websites = more money $$.
Just go one step at a time. Once you'll know how to create websites you'll start learning about which keywords get most traffic and how to pull that traffic.
The smartest thing is to research as you go. Don't try to learn everything before creating your first website.
AND the most important thing: don't stop trying if your first few websites completely fail. In fact, here's a secret most people won't tell you: the most successful marketers also had the most failed campaigns.
