I placed all my corrections between two (), comment if something is not clear.
Is (to) set a date and find the location.
out the menu, (as well as the) entertainment.
input from other(s) and (assign) them tasks to (complete).
mail the invites out(no s).
or event (got underway, I would)
the guests(s) (were) having a good time.
Answer:
"establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our posterity."
Answer:
They celebrate before oedipus finds the truth.
The answer is before because prefix of pre is before. For Example preheat
Answer:
I don't undertsnsd the question so I would say the answer is 10 and 5 years old