just got a aloe vera plant from spane its come designed to travel without soil seeds or fetilizers only sterilized vegetal soil and black sand its quite big but what i want to know is do i repot in soil or do i leave it alone

I assume then that it has no instructions with it. Not clear whether you're saying it's already planted in a pot and that's how it was delivered? If you're saying it was delivered with soil and sand separately, they probably mean you to use what they've supplied. However, I know someone who grows these and she just pots them up in multi purpose compost and they do fine, though she has to bring them in during the winter. Hers are always having babies so she gives them away all the time, I've got one, but its tiny!