Making money online is hard work. To make money online you can freelance by doing work for people such as writing articles, designing logos working on someone's website, doing coding for people etc.
What freelance work you can do depends on the skills you have to do the work.
You can create a website on a topic you're passionate and know a lot about and then place Adsense or other ad networks or affiliate programs on your website and earn money that way too.
If you go the money making website route then it will take longer to get money than it would with freelance work.
It takes a minimum of 5 years of hard work on your website to start seeing any good amount of income from your website.