Final answer:
The first step in creating a business plan is developing a marketing plan, which involves a comprehensive market analysis to understand the target customers and market dynamics.
Step-by-step explanation:
Creating a marketing plan is the first step in putting together a business plan. A marketing plan includes a thorough market analysis, which is essential in understanding the target customers, competition, and the overall market environment. This analysis is critical for making informed decisions and strategizing business activities. While a codicil is related to wills and inheritances, and a technical or capital plan is also important in business planning, they are not typically the first step.