If the moon landing was a hoax, what happened to Apollo 11 after it launched?

It wasn't a hoax. However if I were a conspiracy nut I'd probably just say it was launched into orbit and burnt up a few days later in the Earth's atmosphere or just left to drift in space but if I were a real tin foil hat wearing card carrying nut job I'd say that our alien overlords intercepted it as part of some grand conspiracy. Those who don't accept the overwhelming evidence that the Moon landings are real will not be convinced by something as boring as common sense.

The simple answer is that it wasn't a hoax.

Well, it wasn't a hoax, and what happened to it was all documented as it happened....

After launch it was no longer needed, so it disappeared into thin air (not space, since space is a hoax too). The money NASA spent on it rematerialized so they could build the movie studio and futuristic CGI technology they would need.