Verse 9 is well known:
"In their hearts humans plan their course, but the Lord establishes their steps." We make plans for our lives. But God must be seen as the director of our steps. He must be the one who guides us. Sometimes this look like our plans succeeding because we are in step with God's will. Sometimes this may look like a change of plans because God had a different purpose for us.
God won't force you to do anything, but He certainly won't bless disobedience. Sometimes when we step off the right path, we face the consequences and God brings us back into the right steps for our life. The wisest thing we can do is to get our hearts to be committed and focused on God, so we are already heading in the right direction, and He is our hope and peace when the roadblocks and problems of this world are encountered.
Verse 18- "Pride comes before destruction, and an arrogant spirit before a fall". A prideful person depends on themselves not God. A prideful person is more concerned about themselves than God. Sometimes we believe that God knocks a proud person down. But I think more often than not God just lets the prideful person knock themselves down. A prideful person follows themselves not God and will eventually come to realize they have been following a fool. When a proud person is humbled, I hope they turn to God for the forgiveness and grace they need. He can rebuild their lives with the solid foundation of Jesus, not the shaky foundation of a big ego.