Do you have anything prepared for this? Do you say, no but come back in a week?
Do you say, yes, here are four pre-gen character sheets, let’s play a random short one-shot?
Do you say, no we’d need to spend time prepping for D&D but here’s a simpler tabletop game which uses minis and dice, let’s play this right now instead? (for example, Shadowdark)
Or something else?
In Shadowrun the intro scenario was a shoot out at a convenience store. A simple one encounter with minimal story to introduce the mechanics. They called it a food fight, and it is how I introduce new plays to pretty much any system now. DnD: a tavern brawl breaks out…
Premades are great for instant play, but if they want to get more invested, the food fight is also a great way for them to get to know their class mechanics too.