Please explain how a punit square works, I have a major test on it and im confused

The image is attached but it might be hard to understand because it's hard to explain

One letter from each parent are combined to create a genotype of one possible offspring. Example: G (from one parent) + g (from the other parent) = Gg (genotype of offspring)

Capital letters are dominant and lowercase letters are recessive

Dominant traits mask recessive ones so when the genotype of the offspring is Gg, it will be green because green is dominant over yellow

If you need any help with the questions on the test you can post them and i'll help

the scientific method.