Realm Creation Guide

You should learn normal astral projection first, or it will be useless to try and make one.
practice by making energy/psi balls, casting spells, ect. just practice and you'll get it.

So if we learn something there, say programming, we would know it here? And if we copyed here, then could you see the effects of some actions before anything happens? Also, wouldn't the military use astral projecting for scouting, or spying?

if you mean the exact same planet it wouldn't work because it does not mimic the real world.

I'm about to creat me realm full of dragons

I have done it before also. :)