What is a Primary Resource?
Short Answer: It depends on the project
Primary sources are contrasted with secondary sources, works that provide analysis, commentary, or criticism on the primary source. A primary source is "first-hand" information, sources as close as possible to the origin of the information or idea under study.
Secondary Sources provide detailed summaries of topics- try to search GVR entry or Wikipedia page for a topic, and written down names of important people/places/incidents, and searched for [those] + primary sources in Google.
What is an archive?
Plural noun: archives
A collection of historical documents or records providing information about a place, institution, or group of people.
Which archive has the records you need?
Sometimes a whole archive will be devoted to one issue but many times an archive will own many collections. So how do you find archive materials when you don't know where to search?
TIP: You most likely won’t have the time or the ability to visit various archives in person so filter your search results to "digitized records" only.