If you are not really happy with the available themes then you can start developing your own with some basic php knowledge but since you said you are having no knowledge on programming nor designing then we can go with the following option : Using WordPress theme Generator Online
This option is for people who want to generate a very simple blog theme with the help of a wizard along with some small changes and download the whole theme in a very easy format. The advantage of using this option is that you can design your own theme based on your requirement. You can select the width of the theme ranging from 100% width which means fluid to fixed sizes of 750px, 950px & 984px. You can decide what kind of sidebars you would feature on your blog and select them from the drop down options available.
These generated themes are very much recommended because they are very light in size and load super quick on any browsers and on slower broadband connections. You can even do a website speed test once you active these new design and see if your blog loads more faster in this new design.
