Since primary sources are sources that are directly connected to the subject being researched, you have to go as close as you can to the subject and chose them based on how pure they are.
If you're researching about a person, a live interview with no interruptions could be considered a primary source. A speech given by that person would as well. Same goes to an autobiography.
But talking to someone who knows that person or reading an interview in a magazine that can have gone through editing is second source already.
A library seems to be a great place to find primary sources, since it can have books, journals, and more.
