I have client side ability to change viewing size 800-1200 and the photos are now showing off center to the right is there a way for me to address this so the photos are centered on the page properly?

You will have to modify the CSS of your theme.

okay and I access that under what tab?

There is no tab to change the CSS.

Each theme has one ore more `.css` files. For instance the Default theme has four. One for each theme "personality". (located in the [i]styles[/i] folder)
It's the `.css` file you have to modify to change the layout of your theme.