The discovery meeting brings you and the marketing professional together to talk about different marketing services offered. They will be looking to understand your business better _ in its current state and your future vision. The marketing consultant will also explain the variety of marketing services offered so you will be better able to understand the final marketing plan when it is delivered.
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.