God’s desire is for our happiness. As we follow that trail of happiness and peace, we are led to the vocation God has for us. Each one of us has a vocation to holiness, from our baptism. From that calling, God calls many to a vocation in service of others: either one person in marriage, with a family that might flow from that, or a more open-ended love that seeks to love Christ in whoever He sends us.
Some good discernment books:
“What Does God Want?” by Fr. Michael Scanlan.
“Discernment of Spirits” by Fr. Timothy Gallagher.