If the sources don't match, don't assume that the information they provide is incorrect. If you have two different dates of birth, is it possible there were actually two different people? There are many reasons records can give differing information, but keep yourself open to the possibility that records you think are for the same person are actually for two different people.
Don't force everything to match. There may be two individuals hanging out in the same location at about the same time who are about the same age.
This is a topic we occasionally visit in Casefile Clues in more depth than we can here in a tip.