Similar thing happened to me first time round. At the tender age of 12 me and a mate decided to smoke AT MY HOUSE, while my folks were asleep!
We, in our ignorance smoked waaaaay too much. Needless to say I had a terrible experience. I woke up the next morning to find my mate passed out in my bath tub, with all my dirty laundry covering him!?
Anyway, weed very often doesn't have ANY EFFECT the first time smoked. So, we smoke more and more until we get utterly, frighteningly wasted.
You're thinking will be "cloudy" for a few days. You may be moody and irritable.
Just, as already advised, drink lots of water and eat some fruit and veg to load up on the good stuff.
My first experience with weed was so bad, I was taking ecstacy, LSD and mushrooms before I touched another joint. I was too damn scared.
If you do decide to smoke again, remember, MODERATION is a word you'll need to become aquainted with.
I'm a regular smoker, and I find when I go through patches where I smoke a lot, my memory is awful, my thinking unclear and I'm overly lethargic. Note, these are after effects, not how I get while stoned.