I am new to Ubuntu and have tried using the Ubuntu Software Center.
It shows up but once it opens it doesn't respond.
Can you help me figure out how to reset this application (Ubuntu Software Center)? Thanks!
To be honest, I'm not sure why anyone new to Ubuntu would be using an unstable development version. There are and will be issues peculiar to 13.04 that the dev team and others are working to resolve, before it's official release date. This might be one of them.
My suggestion would be to wipe 13.04 and install the 12.04LTS version. This will give you the most stable version of Ubuntu, and the version that will be supported for the longest time. It'll also be the best way to learn about Ubuntu & Linux in general. Re-installing is a bit of a drag I know, but for you as a noob it would be well worth the effort. :-)