How long did Neil Armstrong have to train before he went to the moon?

Answer 1

Honestly, decades. Even before he was an astronaut, he had years of training as a civilian pilot, then a military pilot, then a test pilot--all of these experiences helped in various ways to his selection by NASA as an astronaut. Neil became an astronaut in the early 1960's; of course this training helped specifically. It was probably around 1967 when all Apollo astronauts began generalized training for lunar missions; and then specific training for any particular mission, a year or more.