The Rosary can take some practice and perseverance at first. It is made up of two things: vocal prayer and mental prayer. A common complaint is that the Our Fathers and Hail Marys are repetitive, but that is exactly what helps with the mental prayer…
The Rosary is a meditation on the life, death and glory of Jesus Christ and his Most Blessed Mother. There are 20 mysteries divided: 5 Sorrowful, 5 Joyous, 5 Glorious and 5 Luminous. During each decade of the Rosary you should try to place yourself in the scene of that mystery. Think it through on the part of Mary, Joseph, the Lord Jesus and others who were there.
It is also a common practice to offer the Rosary for a particular intention, and you can hold that intention in your mind while you pray.
Catechism 971, 2673-9.