There were 17 Apollo missions. The first one to land on the Moon was Apollo 11 (with Neil Armstrong, Buzz Aldrin and Michael Collins).
Apollo 13 was supposed to be commanded by Alan Shepard. But he was replaced by Jim Lovell 6 months before take-off.
The crew was composed of Ken Mattingly and Fred Haise. But three days before launch, the flight surgeon thought Mattingly may have the measles, and replaced by Jack Swigert. Swigert was the first (and last) bachelor in Space.
The Flight director was Gene Kranz (who also directed Apollo 11 and the first Shuttle mission).
When they were headed for the Moon, an oxygen tank blew and they vented oxygen into Space. They decided to abort the mission. They used the Moon gravity to slingshot back.
They were also short of energy. They shut down heating, the lights, the computers… they had to maneuver by keeping the Earth in the window.
They were suffocating and had to adapt square filters on round pegs. Then Haise fell ill. And Ken Mattingly found a way to gain energy: drain it from the LEM batteries.
Later, Jim Lovell became Flight director (but he directed were Challenger and Columbia). Fred Haise was supposed to go back to the Moon on Apollo 18. Ken Mattingly went to the Moon on Apollo 16. Jack Swigert was elected to congress, but died before he took office (officially from cancer).