Can a 17 yr old have a stroke? If so what would symptoms be

Yes. Anyone can have a stroke. Check out stroke.Org for detailed info.
Yes but. It's possible, but unusual. Symptoms can be anything neurologic, since a stroke involves the sudden death of neurons (brain cells) due to ischemia (not enough blood flow, or a clot) or hemorrhage (bleeding). Strokes in younger people need to be investigated. Please call your doctor if you're having any symptoms worrisome for stroke = many possibilities, bc anywhere in the brain may be affected.