Can I customize the free version? How?

I am trying to use the soliloquy theme on my wordpress site and I am having trouble with the customizations. Do I need to download the full theme (paid theme) in order to change things? Or can I customize the free version with my own logo and colors?
The sample images won’t go away and they are loading on top of my image slider and other images. I can’t get my own images to replace the samples on the front or in the pages. It looks like a total mess right now. I also can’t remove comments from pages or change the size of the images. Maybe I just have no idea what I am doing, but I do love the potential on this theme, and I don’t have the money to hire a designer. Thanks!