What can I give my two year old for a cold and cough?

Time and patience. Colds go away in spite of, not because of, all the over-the-counter remedies we use. Some feel better with humidified air, but make sure your humidifier is clean. Decongestants and cough suppressants (used short term) can reduce symptoms of runny nose, but cough meds are better at helping you sleep than at reducing cough. Make sure your little one drinks enough fluids to avoid dehydration.