WordPress Website Templates
Find Professional WordPress themes Easy and Simple to Setup
If you want to edit CSS code
Go to the Appearance -> Editor -> style.css
You can also use your own custom css code
Go to the Appearance -> The Options -> Basic Settings -> Custom CSS
If you don’t want to use sidebar, you can use full width page template to show your products.
Just edit the page and select Full Width template from the Page Attributes panel which is on the right side.
Please check the documentation to customize the theme