Selling large plastic sheets cut to size

I am purchasing large PVC Sheets, and cutting them to 12″ x 12″ squares.

Can I sell this on Amazon? Do I need to ‘register’ my brand or a trademark in order to do this? (no trademark) Do I enter the material in as the ‘brand’ of the source material from the manufacturer? Am I correct to assume I will not need a UPC since this is an original product?

Thank you in advance!