setting for first use

Hi, I bought Pro Plans but I don't know how it works. I would like to create paid articles that are part of a category. as in the example
I wish I could sell individual items, or a sub-category with a discount or the main category discounted.
Example: 1 article to read 10 euros.
1 sub-category with x items (30% discount) x * 10-30%
Main category total items * 10euro-50%

thanks
Roberto