There is no definite evidence to his authorship of this Psalm 1, but a strong similarity between the Proverbs and Psalm 1. Well, at this time we will say that Solomon is the author.
Story behind the Psalm:
The father is talking to his son. Let's say this father is Solomon and the son is Rehoboam, who succeeded him on the throne. He is teaching him the way to blessedness and is warning him about the destruction of those who follow evil.
The Jews used the first Psalm as instruction to children in family worship. It was memorized by each child and quoted and sung over and over. The father gathered the family together also and explained the recipe for daily success from this Psalm 1.
It is interesting that the word "blessed" in verse 1 is a plural word. It means that there are a multiplicity of blessings which rest upon the person who observes the five conditions for success and prosperity.
walks not in the counsel of the wicked
nor stands in the way of sinners
nor sits with scoffers
but his delight is in instruction of truth
meditates day and night.
Being blessed is in Psalm 1:3
you are going to be like a tree
you are going to be planted
planted by irrigation canals
going to be fruitful
In all you do, you will prosper.
In Jesus Name, Father God, I come to you. Help me to be a Psalm 1 person, especially meditating on your instruction of truth day and night. Help me to be stable as the tree planted by the streams of water.