Ok Adventurechick, delete 'Portfolio Press' theme from your themes folder (it is very important to delete it). Download links given below:
1. https://www.box.com/s/9c5lcb3t6cfmerucujjr - This is actual theme file. You can install it directly using your theme install feature in admin panel->appearance->Install themes-> search for 'Portfolio Press' and install it. Or download this file.
2. https://www.box.com/s/qvr7rpsvrnwnbqw4z4m4 - This is its child theme. Download it.
Than go to admin panel->appearance->Install themes->upload and upload theme in order. (don't need to upload 1st file if installed it using above told method.
Than Activate the 'Portfolio Press Child Theme'. It should be displaying correctly now.
Note that we have removed sidebar and increased width of tags archive only. If you want sidebar to be removed from all pages than wait for my next reply. I will remove side bar from all (categories, posts, archives etc.) and will give you a link to download it.
If its not not working than please notify me. NOTE THAT IT WILL REMOVE SIDEBAR AND INCREASE WIDTH ON THAT PARTICULAR PAGE ONLY. IF YOU WILL CLICK ON ANY IMAGE ON THAT PAGE AND GO TO THAT. SIDEBAR WILL STILL BE THERE. WAIT FOR MY NEXT RESPONSE TO REMOVE SIDEBAR FROM EVERYWHERE.