A good rule of thumb to protect yourself: be suspicious of anyone that asks you for your time or money.
The world is dangerous. There are many sophisticated scams, and it's hard to tell genuine goodwill from malice at first glance.
What you want is to identify MLMs, bad faith actors, conmen, false advertising, and more. These schemes often focus on exploiting our ambition and gullibility. For example, young students keen to follow up on their dreams.
Most simple scams, at least, will end up asking you for what they really want. They'll pitch you soon enough for cash, a payment, or more time to follow up with some bait they dangle.
This is a simple rule that holds universally, and isn't tiring to implement.
It might seem like an exhausting approach, but healthy skepticism isn't about judging people unfairly. It's more about being an objective and reasonable judge of character.