First of all I would say that if you know anything and want to earn online then Google adsense is a best choice to earn.
You just create a google profile create your own or allowed content like me I have my Youtube channel rishikeshojha and I have uploaded videos. I have linked my youtube to Google adsense. This is my starting so I have earned little amount also.
If you want to use then there are lots of videos on how to use google adsense.
Best of luck