Our adopted bengel/tabby is having problems

A few weeks ago we rescued Whiskey who we have noticed eats a lot of food and then afterwards seems to vomit the pieces out again...It does not always happened but it happens a few times a week. This morning I woke up and noticed he seems to have a watery left eye that is half closed. I can not afford a vet bill this month due to a family emergency earlier  and worried he might be sick. Is there anything I should look out for?

Watch for lethargy, change in play or litter box habits, sneezing with discolored discharge, or any discolored eye discharge.  All of those warrant a trip to the vet immediately.  As for the throwing up, that might be a food allergy and could possibly be helped by a food change.  Do you feed him wet or dry or a combination of both?  How old is your kitty?

There is always dry food in his bowl and we give him half a small tin of wet food at night. He is about one year now

Changing his dry food gradually might help with the vomiting.  Keep an eye on his eye and see if it gets worse.  If it does, then he needs to go to the vet.  You don't want to mess with eye problems.

For the vomiting problem it may be that he's eating too quickly.  You may want to try a trick I read about here somewhere to put a golf ball in his food bowl.  It forces them to slow down their eating because they have to eat around the golf ball.  However, like stephanietx said it could be from a food allergy, so slowly changing his food as suggested might be a very good idea.  Just make sure you do it slowly to prevent any further stomach upset.

As for the eye, I agree that you don't want to mess around with eye trouble because it can go bad quickly.  You can take a warm damp cloth and GENTLY wipe his eye.  However, if the problem persists for more than a couple of days I'd try to get him to the vet to get his eye checked.  This is especially true if the discharge has any color to it.  Anything other than clear tears can be an indication of a problem.  It's possible that one of the other cats scratched his eye or he got something in it.  Either way, if his eye is scratched he'll probably need some antibiotic ointment and it's good to get the eye checked to make sure that it hasn't caused any permanent damage.