Sick dog

I’m worried about my dog. He’s thrown up 4 times today. We called the vet but they can’t get us in until later. He’s walking around whining and throwing up. Is there anything I can do for him until we can get him to the vet? ☹️

Yes he has peed normally since throwing up, but I don’t think he has pooped.

Update: Thank you both for your advice! The vet said my dog’s liver enzymes were high, and he gave us some medicine for him. He should be okay.