Is it true that NASA is hiding something from us about the moon and other extraterrestrial things?
What evidence have you for that idea? If you ask the question, you must have some evidence that they are hiding something? Can you present it so that we can comment, one way or the other, on it?
NASA, as a research organisation, naturally has a very open culture. On the other hand, NASA works with military organisations which have secrets they need kept and commercial organisations which would like their arrangements confidential. Also, because of the nature of its research, it will have many cranks liable to misunderstand any piece of information which is at all confusing. So there will always be a certain caution in the way it releases certain information.
So you need to show what it is that has aroused your suspicions to ask this question.
There is no evidence that NASA is hiding anything, However there are credible stories from NASA personnel about evidence of ET activity being buried, It is also clear that the CIA instituted a policy of disinformation and debunking in 1953 as a result of the Robertson Panel Report.
No, that isn't true. There's no evidence that NASA is hiding anything, and there's no reason why it would.
A lot of people spouting the same paranoid-conspiracist nonsense doesn't make it any more true than it would be if nobody were spouting it.
You can't make something true by repeating it over and over again, but there's never a shortage of people who try.