I know economics and numbers can look scary. I studied business for a year, so i can tell you is not as hard as it looks.
I can explain some basics:
The market: believe it or not, the market is the people. Their behavior affects the value of stuff.
Supply: how much of a product/service is being offered by the population. More supply means lower prices.
Demand: how much of a product/service is wanted by the population. More demand means a higher prices.
Supply/demand: is what people are providing or selling(supply) vs what people buys/wants(demand)
Cost: how much money costs to make a product or to by the things needed to make a product/service and the expenses to maintain it functioning.
Price: this one is obvious, how much do you charge?
Profit: you want to gain more that what you spend to sell whatever you want to sell.
So, for example, if you want to make merchandising for your comic, you first need enough people interested (demand) before even thinking about hiring a manufacturer. And you need to sell for a price higher than your costs to make a profit.
Marketing: the basic strategy about how you want to atract buyers and make your product/service visible.
Advertising: how you show your brand/story to the world. This is deeper than marketing, you basically want your brand to have a strong belief and to choose wisely the media you want to share it.
This was a quick brush, hope it helps.