Can anyone astrally project or are there thing's that would prevent this ?

Samael Aun Weor said in his book Aztec Christic magic :

"If you faithfully practice each one of the exercises that we have taught in order, for at least six consecutive days, you will soon project yourself within your Astral Body, this is if you are a respectable person, that you neither abuse of liquors nor tobacco, that you do not propagate gossip, that you do not enjoy making fun of your neighbors, that you love and respect every living being."

However he also stated that members of the black lodge can also astrally project.