If you know javascript then it is not enough you should also no some more programming languages. If you are good in javascript then head towards react native from which you can also build iphone and android apps. React native is developed by facebook and popular android and iphone apps like facebook,instagram,skype and many more are made through it using javasscript.
The easiest way to make money is find a doctor, businessman, restaurant near you. For example my friend made a website for the local doctor on which when ever someone wanted an appointment then he calls the doctor and fix the appointment. In a nutshell, he is managing the website and doctor gives him $400 per month. So, if you find at least three doctor then you can get more than $1000 only for managing websites. I think it is the best idea.