Yahoo! has not archived GeoCities member web sites, but you may be able to find an archive of your visible web pages on the Internet Archive.
The Internet Archive, a nonprofit founded to build an Internet library and archive the public Web, has been indexing GeoCities pages for years as part of its normal collection efforts, and worked to archive as many GeoCities web sites as possible before GeoCities closed on October 26, 2009.
To see if your site was archived, please visit the Internet Archive GeoCities site and enter your GeoCities web address in the search field provided.
Please note that the Internet Archive has indexed GeoCities sites independently, as a public service.