IMO those are theoretical questions, not philosophical.
Most of the answers so far are not so much philosophy but theology. They blend in Aquinas, but most philosophy professors would want to keep them separate, because most of the philosophers of the last 300 years have kept them separate. I hope your professor accepts theological answers to those questions.
God made man and from the Garden of Eden came the fall of man. God formed man in His image. We aren't merely ants, but a little lower than the angels, but His loved Creation.
Why are we here?
As part of an appeals trial to settle the Angelic Conflict. It will become obvious to all Creation that God's Judgment is Perfect and the eternal damnation of the fallen angels and those who have rejected His Provision to the Lake of Fire for all eternity future is indubitably inevitable, Righteous, and Just.
Where are we going?
Every knee will bow to our Lord and Savior Christ Jesus. He will open the books, looking at the Book of Works and the Book of Life. Those with their names blotted out and do not have any good works by Divine standards of having been performed in fellowship with God, have no salvation from eternal damnation. Those who do have such good works and their names in the Book of Life will receive eternal crowns at the bema seat.
Kant can’t.
Just an observation - “We are like ants to God.”
Biblically, that isn’t the case at all. In fact, the hairs of your head are numbered. Matthew 6 is one of my favorite chapters of the Bible, and it is the antithesis of ‘we are like ants . . . ‘
For Christians, the ‘who’ question becomes sort of easy I guess: we are the manifestation and instrument of the will of God. Fearfully and wonderfully made, and all of that.
Clinically, the ‘where’ question becomes “Heaven” in the long term, but in the short term, it becomes “where He wants us to go”, but there is nothing easy or comforting in that answer.
I’m watching my kids discover their gifts right now. It’s a science so inexact that you can’t not wonder about God’s hand in it.
Religion colors the philosophical a great deal, I’m afraid.
There’s the old example of the Buddhist who witnesses a Tiger and her cub at the bottom of a cliff. The Tiger is injured and cannot care for the cub.
The buddhist, upon seeing this, throws himself from the cliff.
Hearing the reasons why this makes sense to a buddhist is interesting.
Normally, the way one would respond (humorously, or less so)to any direct inquiry as to one’s philosophy is as follows:
I. Kant.
God.
Why are we here?
To know, love and serve God, so that we can be reasonably happy in this life,...
Where are we going?
And to be happy forever with Him in the next.
That's the short answer. 8-)