Everyone makes the same mistakes when starting out in business, including the belief that you must know everything about your business. However, without prior business experience, it's unlikely that you'll have a comprehensive understanding of all aspects of your business. Even if you know your function within the business, you'll likely feel pressure to know everything. Business coaches, advisors, Dragons' Den, and accountants may make you feel inadequate, but they, too, have flaws in their businesses.
Experienced businesspeople may ask unexpected questions that can teach you valuable lessons, but they should not make you feel uncomfortable or incompetent. At the beginning of your business journey, you're as inexperienced as a newborn child learning to walk. You'll learn from falling over a few times and discovering what not to do.
If you don't have the financial means to hire a team of experts to run your business, you'll need to take on various roles yourself. Every business needs a product or service to sell, a channel to sell it, logistics (if you have a product), marketing, and accounting. To determine the cost of creating a product, such as jam, you need to account for all expenses, including ingredients, cooking process, labor, packaging, transportation, and sales. Once you have an accurate understanding of the costs, you can determine how many units you need to sell to break even or make a profit.