To start making money online you can try blogging, making Youtube videos, run a website, start a web hosting business, start an ebay store, sell stuff online.
Sell stuff through Amazon.
Blogging is a good way to make money online but it's a slow process and can take a few years or so of blogging daily or at least every week or so to make money.
However some people are so good at blogging that they sometimes make money in the first year or so of blogging.
You can also make money through Fivver or other websites that you do work online for people.
If you get enough people paying you to do online work then you can make some decent side income or even a full time income.