Dreaming is necessary during sleep.
If you didnt take psychology during high school, do so.
They will tell you everything you want to know about why you dream/ don't have dreams.

You actually have more dreams than you'll ever know about when you sleep.
You just can't remember all of them when you wake up, dreams come from your subconscious mind.
Try thinking about something before you go to sleep, and concentrate on it as you fall asleep,
sometimes you'll dream about whatever it was you were concentrating on, along with a bunch of random shit
your mind throws in the dream as fillers.