There are lots of methods on how you can earn money online, and it depends on you on how you'll work into it.
First, PTP or Paid to Promote, site type of website will give you a unique link, and you're going to promote it to social media, or any pattern where you can get lots of views, some of them accept traffic exchange, and some aren't that will ends you being banned
Second, Paid to Write, There are forums that will pay you on every thread, or reply you made and there are sites that will ask you to write TOP 10 LIST, others will ask you to create an article and pays you for every article got approved.
Third, Create a website and put an ad into it, there are sites accepts CPM and CPC, CPM stands for Cost per mile and CPC is Cost per click, In CPM you will earn for every view you get, and CPC you'll earn for every clicks you earned (Note don't click your own advertisement!) Or you can go apply on Adsense
Fourth, You can try working with other people, There are sites will ask you to submit your resume and once you get to approve that is the time you will start earning by doing your job, There is also a site wherein you'll upload what task you can do, and wait for orders!