You could actually slow down the healing or even cause a scar. Washing also makes you more pleasant to be with. If you don't wash - you start to smell. Melanin is what gives skin its colour and also protects it from the sun. People with dark skin have lots of melanin and their skin is better protected.
Sunlight activates the melanin in paler skin, causing tanning or freckles.
Too much sun, though, can burn skin and may damage it forever. Keep it covered in the sunshine - with clothes, a hat and a sunscreen cream. Every part of the body, except the soles of the feet, palms of the hands and lips, grows hair. This is completely normal and most of the hairs are too tiny to see. For medical advice, or if you're worried about your health, speak with your parent or guardian, or your doctor.