Gallery Problmes

This is my first template and on my gallery page, despite having chose 2 columns, it displays only 1. I have already tried removing the borders and this does not fix it. Also, despite having specified link to the image, it links to the attachment page. The file functions.php is much more extensive than I am used to. This is from the sandbox theme. There is also an attachments.php file. My CSS is much stronger than my PHP. Any guidance would be very much appreciated.