Catagories/Pricing

I'm sorry if this has been asked before....

I want to set up my store so that all the products are at this top level without categories. When I do this, it says that because the items are at the top level pricing will be affected. My question is how? And is it possible to make it so that doesn't happen?

That message is warning you that if you have products at the top level, then try to create categories, you'll have problems. Might be better to create one category and place all your products in that.

OK, so how do I make it so when somebody looks at the cart, that one category is the only category they see WITHOUT the category banner?

Not sure what 'category banner' means, but if you turn off the Categories sidebox, and the Categories-Tabs Menu in the header in Admin - Configuration - Layout Settings there shouldn't be any reference to the category.

And set Configuration > Layout Settings >
Categories - Always Show on Main Page -> set to 1
and
Main Page - Opens with Category -> set to your category's id

if you want the products to show on the homepage.