Got dizzy after standing up from a lying position too fast. is it normal to have a weird feeling in my head afterwards? and what are the dangers of standing up too fast other than the potential to faint?

The main danger is fainting if the blood pressure drops too low suddenly. If this occurs usually the heart rate accelerates significantly to compensate which is a condition called POTS( postural orthostatic tachycardia syndrome. I recommend having his physician check his blood pressure and heart rate sitting and standing up quickly to document the reason for his symptoms and advise him accordingly