My First week of Aperture Priority

Aperture is the Size of the whole in lens that allows either more or less light into the camera.
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system’s optical power. A positive focal length indicates that a system converges light, while a negative focal length indicates that the system diverges light.
Aperture is the Size of the whole in lens that allows either more or less light into the camera.
So here I am a Noob with a fancy camera trying to improve my camera Skills. How hard can it be right?