The opening nine chapters offer longer poems or odes about the nature of wisdom or the value of wisdom. Some speak directly to the "child" or student who is supposed to learn. One of the most interesting is a poem allowing wisdom to speak for herself, where wisdom is presented as the first creation of God in the universe.
After these chapters, the remainder of the book is a collection of loosely organized pithy sayings, usually only a sentence (or verse) each. Some offer a twist or something unexpected. Some are humorous. Several have become part of conventional wisdom -- so much so that many do not realize they originally were written in Proverbs.
While it is impossible to encapsulate all 31 chapters of Proverbs, there are certain recurring themes that deserve attention. Foremost, true wisdom comes from God. Left to our own devices, humans are limited; if we are to become wise, we must humbly and persistently seek God's wisdom through God's teaching. Sometimes this is challenging, but it is ultimately rewarding. Wisdom leads to the good life and protection for the hardships that people who are foolish, unjust, or evil eventually face. While good living/action/speaking is a source of light, joy, and hope, bad living/action/speaking is a corrosive force in the world, corrupting the things it comes into contact with, including the one lives/acts/speaks badly or foolishly.