I vomited dark yellowish green bile. I also hurt on the right side of my stomach. I've been taking tylenol (acetaminophen 500), could I have toxicity?

Concerned. You need to be evaluated by a physician. Your potential problems include gallbladder infections, ulcers, pancreas inflammation and depending on the amount of tylenol (acetaminophen) taken, tylenol (acetaminophen) overdose.
Toxicity not likely. If you have been taking tylenol (acetaminophen) according to package instructions and you don't have systemic disease. But right sided abdominal pain could mean appendicitis, so get to a doctor fast. If it bursts, it will cause peritonitis and septicemia.