I am painting my deck with metacrylics paint do I need to clean between coats of paint
The only reason you would need to clean between coats is if you couldn't finish the job and had to wait so long that the deck got dirty again.  If you're putting the second coat down right after the first is cured, and you haven't had a dirty rain or anything, you should be fine.

Other than that, follow the manufactures instructions for a second coat.  Some products might not require you to wait for a full cure to recoat.