Alrite lets say i didn’t understand things very clear that happen one day like 3 years ago. Could i viualize that moment in my dream and replay it or run through it(relive it?
Basicly can i access my memories? 
In a LD, you could do that. But beware, your mind will alter it as it sees fit.
It might not be like the real thing. How well you remember that certain moment and your feelings about it may alter the experience.
Yes.
You can also create entirely new dream scenaries out of your own imagination, not just memories.
thank you
thats really cool