When the Psalmist identifies God as a Shepherd He is, at the same time, implying that we are sheep. In fact, He is and we are.
You don't have to know much about sheep to know you wouldn't want to be one. Sheep are dumb, dirty, and defenseless. The fate of a sheep depends upon his shepherd. If he has a good shepherd the future is his friend. If not, his future is not so bright.
The 23rd Psalm is an amazing Psalm. It is the favorite of many many people. This Psalm is a sheep bragging about his shepherd. And it begins with the words, "The Lord is my Shepherd." In the Hebrew it is "Jehovah-Rohi." The Eternal God is my shepherd.
He is our guide. He leads us. He feeds us. He comforts us. No other name of God carries the tenderness and intimacy of "Jehovah-Rohi".
When we need to be reminded that the Lord is taking care of us, we can come to the 23rd Psalm and praise Him as "Jehovah-Rohi".
The second part of that verse should be translated, "I shall not have needs." Actually, you're wants aren't even discussed here, except in the translators' choice of words. The whole point is that taking care of our needs is God's responsibility. That's His job. He's volunteering for it. He's good at it. We need to let God do His job without needless harassment.
Herein is the inspiring point of this Psalm. If you are a sheep, and you are. And if a sheep is only as good as its shepherd, and he is. And if the Lord is your shepherd, which He is. Then you are one blessed sheep! And as long as you keep following "Jehovah-Rohi", your future is your friend!