They have never heard of it before? How is that even possible?

EDIT: this should tell them everything they need to know though: https://youtu.be/56sEXfIPM_M

I was introduced to it by joining a friend's server and we started playing together. I think it's the best way honestly. She stayed with me at first and answered all my questions, she suggested I go mining once I had some gear, and then I continued on my own.

Is there really a need to introduce the game? I think there is even a tutorial when you first start a new world.

Ps oh how I wish I could play Minecraft for the first time again. I've been playing it for 14 years now

They could just watch some random let's play too. That's how I was hooked into the game initially

I wouldn't call the scope of the game very large, the name itself sums it up. There's a lot you can do, but it basically boils down to:

You mine, and you craft.
You mine to craft, and you craft to mine.
Food? Mine and craft to get stuff to farm.
Monsters? Mine and craft stuff to make weapons and armor.
Better weapons, armor, tools, etc? You betcha, keep mining and crafting.

If you try to go over every single thing they can do in the game, they will probably get overloaded. There is a lot of content, but part of the fun is discovering that stuff for the first time too.

What games do they know? Can you draw any analogies?