When making a decision we sometimes get nervous that we are going to mess up and not go the way the Lord is calling us. The way to avoid making a mistake is to respect God. This means that there isn’t any part in his plan for you that would contradict his Word. As long as you are wanting his will to be done in your life and living so that your choices support that desire -you can’t mess it up. In His time he will make it obvious which way you should go. 
Psalm 25:12 What man is he that feareth the Lord? him shall he teach in the way that he shall choose.”