Question about GoerliETH?

Hi someone asked me to accept some crypto today as a payment, and told me to download Metamask to do that. Then they told me to switch the network to GoerliETH, and I noticed that was a testnet.

When I told them I noticed it was a testnet, they got a bit defensive. I didn't know this person, and I wasn't sure if they were going to just send me testcoins. They said it was fine, I would be able to just deposit the funds directly into my bank account without any problems or ID (which doesn't sound right at all, tbh) Not really sure how you can discern how something is real or not with metamask, or why I would need to switch networks in the first place????‍♀️

Was this person on a ruse cruise? Thank you so much!