how does jim and huck meet king and duke?

This is back in chapter 19. Huck and Jim are on their raft. Huck takes the canoe to look for berries and these two old men come crashing out of the bushes. They clearly do not know each other. Both are on the run from the law (they are basically inept con artists) and ask to share the raft. Huck has a soft spot for petty criminals and lets them climb aboard the raft. The two old men then reveal themselves to be a "King" and "Duke". Huck obviously sees they are clowns but doesn't say anything.