Since you don't have much knowledge of FE development, I would suggest you keep things Simple Stupid and try to do as much as possible with HTML and jQuery. I have created really complex websites using just PHP and jQuery (sites that have made me 6 figures over time), plus you will learn the real nitty-gritty like DOM manipulation, CSS tricks, etc - which you will need to use anyway at least a few times regardless of the shiny JS framework.
I would highly recommend at this time you don't get sucked into the React, Node, Vue, etc. You will only end up wasting months without nothing to show for it (but maybe I'm just too old school).
Whatever time you have left after that, use it to learn online marketing. Learn about list building, SEO, Copywriting, outreach and affiliate marketing. Because that's how you turn your technology into actual money.