How many people have just landed on the Moon and not walked on it?

None. All 12 astronauts that landed there got out and walked around, mostly picking up rocks.

There were 9 manned missions that reached lunar orbit: Apollo 8, 10, 11, 12, 13, 14, 15, 16, and 17.

Apollo 8 just orbited, Apollo 10 just tested the Lunar Lander in lunar orbit (dress rehearsal), and Apollo 13 had a severe malfunction that meant they could not land on the Moon. The other six missions landed 2 astronauts each.