Far be it from me to dampen your enthusiasm, but you should give yourself every opportunity for success. That's what the planning part of the process of creating your business plan will do. By the time you have pressed your way through it, you will not merely have some neatly arranged document to keep on file, you will have a working tool that addresses the essential factors that influence your future.
Every business plan should focus a lot on the business's potential competitors, because research and analysis of the competition effectively gives you plenty of useful information. It may guide you as to where you should be advertising and marketing, or certain strategies to use or ones to avoid because you see they have been used unsuccessfully by others.