[jcelerier]

But OP isn't a newbie going to coding school, he/she already knows JavaScript and webdev in general ! Of course if you don't know programming at all it's harder (even then, 3 months seems like an awful lot - this year I teach programming to graphic design students and in ~15 hours they are already able to do neat things on their own with p5.js).

To give my own experience, I'm almost exclusively a C++ coder but had to do two Web projects earlier this year, a React one and a custom one, and even though both times it felt like eating nails, it didn't take more than a day to "get in" ; I'm confident that it's be the same no matter the language except maybe APL and derivatives :)