Business by nature is competitive, and few businesses are completely new. If there are no competitors, be careful; there may be no market for your products. Expand your concept of competition. If you plan to open the first roller skating rink in town, your competition will include movie theaters, malls, bowling alleys, etc.
So using a sample business plan for a small business is just one of many ways to make a business plan but frankly I think designing one that will have your business give you exactly what you want is by far the best way.