If you have just bought the domain and no webspace, you don't have to move any files. I haven't bought a domain that didn't come with hosting myself, but I'm sure there was a point in the process where you could have told them that your files were at www.geocities.com/ada-whatever. Check the information you got when buying the domain. There must be an email address or some other way to contact them and tell them where your files are.
If you bought domain and webspace, I suspect you are in trouble. The words "all i know how to use is geocities" suggests PageBuilder. Otherwise Geocities isn't much different from anywhere else. And PageBuilder files don't travel well.
