Dinosaurs existed, there is overwhelming scientific evidence for their existence. They definitely did not co-exist with people, they were extinct well before humans arrived on the scene. We take Genesis very seriously, but that does not mean we read it as a literal, geological record of events. According to some of our great Sages, there were epochs of existence here before the story of Adam, and before our present epoch. Dinosaurs and other extinct creatures were of those periods. I suggest two books on the subject - Fossils and Faith by Nathan Aviezer,and Thinking About Creation by Andrew Goldfinger.
