Everyone is born either left- or right-handed (or, rarely, mixed-handed or ambidextrous). But everyone also has a dominant foot, and a dominant eye.
A few people are left-handed for some tasks and right-handed for others – the so-called mixed-handedness – but that’s quite rare. Interesting side note: we don’t actually know why people become right- or left-handed: genetics, epigenetics, parental hormones, and foetal womb position all seem to play a part.
We also have a dominant foot. This is most relevant for sports that involve significant foot action, like football (duh) and skateboarding. Skaterboarders? Well, when you skate you put one foot in front of the other. The front foot is used for steering, the back foot for pushing. Whichever foot goes at the back, that’s your dominant foot. If your right foot is in the back, that’s the “regular stance.” If you reverse, that’s the “goofy stance.” (Many pro skateboarders can switch between the two, but that’s less likely to be the foot equivalent of ambidexterity and more likely just good training.)
On to eyes. Our brains prefer visual input from one of our eyes, making that one dominant. There’s an easy way to test for yourself which eye is dominant, called the Miles test:
- Look at an object in the distance, with both eyes open.
- Stretch your arms out and make a little loop with your fingers, with that object in the centre of the loop.
- Close one eye. Is the object outside the loop? Then the closed eye is the dominant one. Is the object still in the loop? Then the open eye is the dominant one.
Just to round out the head-holes: ears show dominance too.
Me personally, I’m mixed handed: mostly right-handed, but I throw balls (poorly) with my left hand. I’m strongly left-eyed. On footedness I’m not sure: I have two left feet. How about you?
The Generalist Academy 
