If you want to say the whole rosary it's a little bit more than the Hail Mary. But I have found that just saying the Hail Mary repeatedly is very helpful. I try to focus on the words and what the meaning is that it's trying to convey. Not just saying the words for the sake of saying the words. Below is a link on how to say the rosary. It's quite lengthy but near the top is a short version on how to say it:
The Rosary is a Scripture-based prayer. It begins with the Apostles' Creed, which summarizes the great mysteries of the Catholic faith. The Our Father, which...
www.usccb.org
Also, here is the Hail Mary if you just want to try saying it:
Hail Mary, full of grace, the Lord is with thee.
Blessed art thou among women and blessed is the fruit of thy womb, Jesus.
Holy Mary, mother of God, pray for us sinners
Now and at the hour of our death. Amen.