If God knows what my wants and needs are then why do I need to pray? If  He knows why would I need to ask Him?
These are some really good questions. There could be a lot of answers to them but the most important and simpliest answers are because its a commandment and because of  faith. "And again, I command thee that thou shalt ^apray ^bvocally as well as in thy heart; yea, before the world as well as in secret, in public as well as in private" (D&C 19:28).
Christ is our perfect example and even he, who had the ability to see his Father at any time, even he prayed to our Father. "And when he had said these words, he himself also ^aknelt upon the earth; and behold he ^bprayed unto the Father, and the things which he prayed cannot be written, and the multitude did bear record who heard him" (3 Nephi 17:15). Our Savior who in just a few short hours would be in the presence of our Father knelt down in humble adoration and prayed to his Father to talk to Him and to pray for the multitude.
I am so grateful for the Savior and his example that I have to follow. I have previously written a post on pray. Pray is amazing, it is simple, and it is more powerful than we can comprehend! I love it!