Essentially prayer is where we profess our need of Christ and His solution to our problems. It is also the place where we learn to worship Him and grow spiritually in His loving presence. This is a very simple thought, but one that carries a tremendous truth. God wants us to call to Him. Many times He allows disappointments in our lives with the intent of drawing us closer to Himself.
Prayer is the most powerful tool a believer has.
Nothing compares to it. Although I have given you examples from the Bible to make prayer, don't worry about what to say to the Lord. The Holy Spirit will show you. Tears are just as effective as words at times. I have learned that God is sensitive to every tear we cry.