Dear Ms. Meade,
Thank you for posting your question on History Hub!
We suggest that you review NARA’s "Resources for Genealogists" page: https://www.archives.gov/research/genealogy/start-research/nara-resources , as well as the History Hub Blog titled Suggestions and Advice for Family History Researchers. Also, the FamilySearch Research wiki for United States Genealogy may be useful.
We suggest you first look at decennial Census records. Information about census records can be found on our website at https://www.archives.gov/research/genealogy/census/about. Many of these records have been digitized and are available through our partners. For additional information about accessing these records, you can visit our website. You may wish to search Ancestry or FamilySearch for the U.S. Census. There may be a fee for using Ancestry. Instead, please check for access at your local library as many library systems subscribe to these sites, making them free for their patrons.
We suggest gathering the information you have such as your grandparent's names and any children's names and look for the family in census records. Once you find the family you can then work backwards to find your grandfather in the most recent census following his birth (probably 1910, or 1900 if he was born in the first half of the year). The census is a good place to start to locate parents' names.
We hope this information is helpful!