Answer:
What is filled with air and sometimes a gas, tied to a string and often seen on your birthday?
Nothing specific, but more than a few. This many clustered, together will do.
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
What is red, bloody and smells like an orange?
What you become during a workout?
Two little holes in the side of a hill. Just as you come to the cherry-red mill.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?