When I ask entrepreneurs and small business owners, it is not unusual for not having any marketing plan. I once read that Sir Richard Branson never had any marketing plan when he started the 1st Virgin business many years ago. In fact in one study of entrepreneurship (I couldn't recall the name of the study) was that as much as 50% of entrepreneurs and business owners don't have a business plan and marketing plan when they first started the business.
You need to itemize your budget with breakdowns for advertising and promotions. Include any design, development for needed materials to facilitate the marketing. List the media outlets that will be used to execute your marketing plan and break out the online, social, e_mail marketing, e_brochures/e_catalogs, TV, print, radio, PR, tradeshows, sponsorships, philanthropic partnerships, direct_mail, telemarketing, and other outlets. I would also identify which components that will be completed in house and whether you will have an outside agency to help with your media buying and planning.