Assume it was Darmok and Jalad ordering a milkshake. You take the kid to order a milkshake, point and say “Darmok and Jalad at Tanagra” and now they know. It’s the same way you teach language to anyone. Point to the picture of the zebra and say “zebra” over and over.
Yeah it If you see a link like https://discord.gg/abcdefg123456 it is likely an invite to someone’s server. I don’t see how that could get your email address though.