Bad things we do are guaranteed because of our natural ‘weakness’, but if you do 2 things, humble yourself before God, have faith (going forward as though something is true before you know for certain), then weakness (specific things and in general) become strengths. Many of my weaknesses are now my strengths!
To begin, you have to want to believe in God. One step at a time, look for the presence of God (He is all around), say a prayer (say something like “I want to believe in you, God could you help me?”, if you’re nervous say it in your head), be willing, ask God to help with your doubt.