Paperback book, probably from the 1950s or 60s.
Premise, a colony has been established on a mountain plateau of a jungle planet. (pop maybe 200-500 people) There are ape like creatures living in jungle. The colony is trying to survive on the plateau. (Afraid of the ape creatures, or what else might be in the jungle, so they won't leave plateau.)
The Protagonist (late teens?) is having problems with the colony (I seem to recall the story opens he is barricaded in a hut looking out window with weapons and seeing a body (a friend? family member?) lying dead near the hut. Maybe they were agitating for more exploration of jungle and leaders did not want that, tried to arrest them and killed the other person in the struggle. [Or maybe it was one of the colony police who he killed when they tried to attack him?]
Eventually they agree to expelling him from the colony. And a young woman goes with him in exile. I recall she was always limping, pretty sure it was not from an accident while in exile. (I think she had a genetic problem with her one leg. (too short, twisted, club foot, something like that) so her status in the colony was very low. He was near-sighted, everything beyond about 50 feet was a blur. [Possibly they both were scheduled for sterilization so they would not pass their bad genes?]
So they go exploring and eventually meet the ape-like aliens. I think they eventually can communicate by sign language mimicry.
After awhile they get to the alien village, which had a large open monkey bar/jungle gym structure made of logs, with many levels. I think to stay in the village he had to defeat someone on the structure (knock them off, where they would certainly die in the fall).
The cover may have had a picture of this structure.