There are many ways to earn Bitcoin or any coin online, and if you will be doing it yourself and you're a newbie, you might get overwhelmed. Plan things first before doing it.
There are many opportunities but there are many risks too.
People must know about risks of phishing sites, malwares, malicious files and more. Because if they are not aware of these risks, and are not careful in practice, they will lose their accounts, wallets to hackers. By being careless and chase for bitcoin or cryptocurrencies from online works, they can lose what they already own. It's bad, by chasing something vague and maybe small in value but losing something bigger and more valuable.
Chainsec.io's Scambook and
Cryptocurrency security checklist