What is Holy Water?
Holy Water, is water that has been blessed by a priest. It's called a sacramental because it's an outward sign of faith of God's grace and blessing shown to us in a tangible way.
EXERCISE: Bring a special container of water to Mass on Sunday and ask your priest to bless it. Keep the Holy Water at home and bless yourself with it (by dipping your fingers in the Holy Water and then making the Sign of the Cross) regularly (such as before bed, or before leaving your home).