What if I miss God's will?
Making a poor decision doesn't mean we're forever out of God's will. That's part of the beauty of Scripture: It has story after story of people who make bad decisions, but God still uses them mightily. Just look at Abraham and David. They both did some things that were clearly wrong, but God worked through them to accomplish great things. God can use all of our decisions, whether they're right, wrong, or neutral.
Also, we need to remember God is our Father. God is not here to condemn us, but to help us become more like Christ. If we are focused on Jesus, and on holiness, some of those other things will fall into place. God is not a cosmic trickster who only gives us one shot to get things right.