I like to study the Bible and wrestle with its words. I must fit it and find my place in it. Jesus has promises contained here that I need to understand, and commands that I must obey, and joy that I can experience, and grace that I can receive. What about you?
The Book of Psalms is full of David's prayers. There are prayers for victory in battle, for forgiveness after sin, and prayers of thanksgiving. Not all the Psalms are written by David, but he is well-represented. Occasionally David falls into self pity. Psalms 113 is one case where he seems to complain, but by the end, he comes back to a place of thankfulness and praise.
There is a Psalm for almost every emotion and situation we humans face. Psalms 119 praises the Word of God and tells how to apply it and how to read it for gaining wisdom and comfort.
Psalms 51 is a prescription for repentance. It details the consequences of David's sin with Bathsheba.
Psalms 23 is the Shepherds Psalm.
Psalms 22 is the one that details the crucifixion. About half way through it changes to the praise and joy of resurrection.
Psalms 103 is a Psalm of praise and joy in the Lord.
Psalm 100 is a song of praise and and thanksgiving. Psalm 101 is a song in praise of mercy and justice. A few Psalms are prophetic, like 22, which gives details of events future to the life of David. A few are incorporated in the liturgy of the Jewish worship. There are 150 Psalms. If you read 5 every day, you will complete the book in one month. Psalms will bless you life and your witness. Try it.