This is how jobs work: the employer pays the employee, not the other way around. As soon as a job offer involves you paying for "materials," or even being sent a check to cover said materials, making a purchase, then sending the difference back, that job does not exist.
On a related note, "cash this check then wire (or bank transfer, or Venmo, etc.) some or all of it back to me," for any reason whatsoever, is a scam 100% of the time.
An online seller giving you their life story is a red flag, especially when it involves convoluted reasons they can't meet in person (they work on an oil rig or are in the military) or can't talk on the phone (recent throat surgery).
Never, ever text a verification code to a stranger; the person asking for this has your username and password for something, and is trying to gain access to an account by tricking you into handing over the code that is sent when a website doesn't recognize the device being used to login.
Tech Support is never going to call you to tell you your computer has a virus. It does not matter which company they claim to be, but it's almost always Microsoft (or "Windows Company" when they're getting it really wrong).
You did not win the lottery if you did not purchase a lottery ticket.
Famous billionaires do not pick random people to give huge amounts of cash to.
A lot of romantic relationships start online now. However, as soon as they start asking you to wire money, or to receive money and transfer the funds to others, cut off all contact because you are being scammed. Tip #3 applies here as well – constant excuses as to why they can't meet in person or talk on the phone are major red flags.
Never pay for a pet that you are not allowed to meet in person first. Zero exceptions. The "breeder" having a website with photos of purebred cats or dogs proves absolutely nothing.
If you ever do fall victim to a scam, beware of recovery scams afterwards. This includes the same scammer calling back to offer a refund (that will still somehow involve you paying them). When you lose money in this way, it's gone. Anybody offering help recovering your losses is just trying to double-dip.
