>>/21075/
Pick one friend and only one. Tell him you test DnD out.
You will be the DM. Pick a system, ain't matter which, maybe older one with no feats and such or the one you're most familiar. Ignore half the rules, forget the half of the remaining ones.
Make up a very simple tale, can be played in half an hour: you have to save a princess trapped in the highest room of a three story keep (norman style tower-castle), basically one room per floor. You get the quest in point A, you travel through point B to the keep at point C.
Remember both of you this is not acting. Playing a role doesn't mean such, tho a player can be asked to act the situation out, but make this tale of yours out of partly hacking and partly problem/puzzle solving one. Make one notable NPC with some personality, and a handful of background ones for the most essential interactions.
Create your characters - yes one for you too. Pick only from the most basic classes: Fighter, Thief, Cleric, Mage. No multi, prestige, whatever. Make them simple with very little personality, make one or two important traits/motivations tho which should influence the PC's. Make yours the supporting character, the Muscle (to help in fight) or the Brain (to give clues), don't get too attached to it, don't create a Mary Sue. Let your Player decide what he wants to do.
Sit down and play.
Now you don't even need dices, you can use a software, there are websites with random number generators, "dice rollers". You don't need cardboard props or maps, it's fine to draw on piece of paper.