Prioritize your goals. If you want to become a bodybuilder, it's going to take some planning when you get started, depending on where you are with your body. Planning and sculpting will be an ongoing process, so it's good to sit down and meet with other bodybuilders and trainers to talk about what parts of your physique to work on.
If you're a little overweight, in the beginning you need to get focused on doing calorie-burning exercises to get your fat percentages down, way before you start worrying about building your pecs into chiseled works of art. Start doing cardio and circuit-training exercises to lose weight.
If you're already lean and want to start building up muscle, start developing your strength training routine, focusing on compound movements first, then working your way up to isolation exercises, targeting the specific muscle groups you've identified as needing work.