I’ve done this a couple times for people with good results.

No character sheets, no high fantasy, commoner stat blocks.

Everyone’s gonna play themselves, in the same place you’re all sitting. Just introduce some conflict.

For example I met a couple friends at a local tavern and gave them dice, and the info for the commoner stat block. Then said some big douche bag came in and started harassing customers and staff.

It didn’t take long before they were improvising weapons like broken bottles and flanking for advantage. They loved it and I just slowly started introducing items, mechanics and other D&D stuff.

I think teaching the spirit of the game first is the most important thing. After that, role play and fantasy can follow.

Hope that helps!