My dog is vomiting food, then yellow/clear liquid. What can I do?

I'm sorry to hear Paulie isn't feeling well. I would withhold food for the remainder of the evening, and then start a bland diet in the morning. Vomiting can have a variety of causes, such as dietary indiscretion, ingestion of foreign material, or another underlying issue. If he does not improve, worsens, develops further symptoms or you are concerned, I would recommend he be evaluated by his regular veterinarian to determine the underlying cause for his vomiting, have any necessary testing done (X-rays, bloodwork) and get started on any treatment that may be needed. Good luck!