A yap is a short, sharp, high pitched bark. Small dogs tend to yap, and can be very annoying for people who live near them.
You yell when you shout loudly. People often yell out to get someone's attention, or because they are hurt.
Yuck is a sound you make when you think something is disgusting. Children often say yuck about food they don't like to eat.
Yum, or yummy, is a sound you make when you really enjoy your food.
Yummy is also an adjective that children use to describe really delicious food.
A zing is a sharp sound, like the sound of something moving past very fast.
Zing is also something that adds vitality or excitement to something, as in "add a little zing to your presentation".