The best way to know what your calling is for ministry is to spend time drawing near to Him and seeking His face, then begin walking out what He puts on your heart.
The wonderful thing about God is that He may surprise you with what you're to do, but no worries, it is He who will empower you and sustain whatever it is He has called you to do.
Get ready to see His power move mightily in what you're doing, to!
God's Spiritual gifts manifest according to His will, so don't box Him in with what He can do through you.
Additionally, God has appointed some to have specialized ministry callings found in the 5 fold ministry gifts in Ephesians.
Some are apostles, which are called to establish and oversee big things of God, some are prophets, which have a calling to hear from God and relay what they're hearing to the Body, some are teachers, which are meant to help express doctrine in simple terms to the Body, some are pastors, which are meant to shepherd and encourage the flock, some are evangelists, which are meant to increase the Body by preaching the gospel.
Please note that everyone can function in all of these callings on a smaller measure personally in their lives, too. For example, when a couple begin to raise kids, God will give them a measure of pastoral gifting to facilitate the raising of their children. Additionally, everyone can hear from God, so Christians, in general, are prophetic people.
It's just that the 5 fold ministry giftings do have specialized purposes for God's big plan in the Body.
Also, some may have a singular calling from out of the 5 fold, so they may be a teacher specifically within a congregation. And some are called to do all 5 in one measure or another.
The best way to know which God has put into you is to draw near to Him and begin walking out the ministry that He has put on your heart.
Also know that many of these ministry giftings He can put into you at any time He sees fit. When you draw near to Him, He will decide when and if to place them within you.
One last note: The 5 fold ministry callings also require intensive training and preparation that God will put one through, or take someone who has gone through great trials which have transformed their character in powerful ways, so God will take the difficulties and make them for good by putting that person into ministry which suits the challenges they've faced.