It is not making a decision between good and bad choices. Discernment involves listening to ourselves, and to God's voice in our lives. Discernment is done by taking time to pray, talk with others whose values and insights you trust, thinking, journaling, and just spending time with yourself. Questions you may want to reflect on as you discern your call may include the following. By reflecting on questions such as these, you may gain a clarity in thought and feelings regarding your call.
Discernment takes time.
Allow yourself to sit with any confusion, and invite God to join you in that confusion. Listen for what God may be telling you. Find a spiritual director who can help you in this process. Or contact a religious community to ask questions. Discernment is different for different people.