Discernment is a big word. It is a sort of impressive sounding word, but how does one practically go about it?
Discernment (in the sense of which we treat) is the process of seeking to know God's will, so that we can do it. This involves multiple pieces, so we can look at them step-by-step, day by day.
Just so you know, I am not using my own wisdom here. Discerning the Will of God, by Father Timothy Gallagher, provides an exceptional explanation and teaching on the art and science of discernment, and I use it frequently in working with young people.
So, what is your question? You may not know, exactly, right off the top of your head. So take it to prayer, and to thought and to reflection, however you do that - in front of the Blessed Sacrament, in the quiet of your room, with a journal, taking a walk. But define your question as clearly in your mind as possible.
What do you want to find the will of God about?