Here is a 3-hour, 5th-edition D&D adventure I ran for my brother and his 3 friends, none of whom had ever played a pen-and-paper game before.
We had an email thread beforehand to make 1st level characters. There is still a lot to figure out for character creation in 5th edition. Some influences as to what D&D might look like were Record of Lodoss War and some images from the grindhouse edition of Lamentations of the Flame Princess.
The characters were all great, with interesting backstories and personalities that were not overbearing. It was a group of naturals. Maybe it helps that they all play Gloomhaven a lot?
My brother had also mentioned the desire to do an "iconic" adventure as his first. After discussion with some friends, and the email thread, I decided D&D couldn't get more iconic than a dragon in a dungeon. So here it is - maybe it will be a first adventure for someone else.
Cartography by Dyson Logos is licensed under a Creative Commons Attribution 4.0 International License.