Do you have a URL for the site so that we may have a look at how it is “screwed up”? ?? Or are you building this locally on your own computer using something such as XAMPP, WAMP, MAMP, etc.
Generally, there is no need to completely start over unless one messes around with the core files and even then, one can always upload fresh copies.
Some more detailed info on what it is exactly that you expect and the theme names you have tried will go a long way in the forum members being able to better assist you if they are able.
