The Catholic priesthood is not a career one chooses, but a calling from God. Young men discerning the call to the priesthood need to listen prayerfully to God and discover where God is leading them.
This process of discernment is a group effort, involving parents, parish priests, bishops and seminary directors. All parts need to be working together to ensure a young man properly discerns God's will. The faithful have a part in this process, too -- praying for the increase of priestly vocations.
Here is a prayer from The Messenger of the Sacred Heart, published in the 19th century, that prays for everyone involved in the discernment process.