There are tons of ways. Assuming that you are asking how to earn money from home, I can only assume you want to make money online using the internet.
One of the easiest ways is to start offering services on Fiverr. You can create a gig for free and begin providing services and getting paid for them. If there is anything you are skilled at you can attempt to sell it on Fiverr.
Affiliate marketing is also an option although it takes real work to make money along with being in it for the long run. I can answer this confidently because I am an affiliate.
You may have to learn a new skill if you don't currently possess any skills that you can monetize. Luckily thanks to the internet, websites like YouTube are goldmines of information. I myself have a playlist on my YouTube channel on how to start a website design agency: https://www.youtube.com/watch?v=6Kw_oXfHKeQ&list=PL4U8Oj1w4tM3whmT7UnP35r9l_MVJK03n
Honest short answer to this question is this: Pick something you know you can stick with, take this seriously (because making REAL money online will require starting a REAL business of some kind), and go with it for the win.