There are good translations and not so good ones.  The sons of God were angels, the ones (evil spirits)  which left their original realm to co-habit with women have been placed in confinement  as the apostle said. It is thought by some (including myself) that the offsprings of these spirits and women are the demons which have inhabited people since then.  So there are evil spirits and demons.

Regarding the time span of Genesis, there are a few ideas. I’ll tell you that only a short time span matches the amount of dust that is on the moon.  When the moon landing was in planning stages, there was discussion about how much dust the landing craft would encounter.

  Because of the evolutionary nonsense propagated everywhere, it was thought the craft might disappear in a hundred feet of moon dust - since the moon was supposedly millions of years old and the rate of cosmic dust falling is a known value.

 During and after the moon landing there was not a peep from the media about the little amount of dust (about an inch and a half).  I guess it shouldn’t surprise anyone that the level of dust there was totally ignored since it shows the lie about the supposed great age of the moon.

 I didn’t pay a lot of attention to the moon landing at the time because I thought these guys were crazy, but years later, the creationists pointed out the lack of dust on the moon as a yardstick for counting age. Not much dust= not much age.
 

Dinosaurs and men were contemporary. I think the nature of these creatures was changed, from eating grass and organic stuff before the flood- to whatever they could find- after the flood occured, and for this reason people killed them off.  The dinosaurs that weren’t killed  off were the ones out of reach- in the water.  Remember that these reptiles would grow with age, so they didn’t begin life in gigantic form.  And before the flood they had more than a thousand years and a perfect environment to grow in.  I’m also sure Noah didn’t bring the big ones into his ship.

There are many good authors dealing with creation- check out some online or at a Christian bookstore.