Ok so I figured out how to get MissingNo. Before we begin, I need to tell you I did this on an Emulator. Enter the walk through walls cheat before getting your starter Pokemon. Walk through the trees at the edge of town. Go into the wild grass. When a wild Pokemon appears, you send out MissingNo. Be warned that it doesnt have any moves, and you black out in one turn. You end up back at your house. And thats how to find MissingNo.!