This is a personal question, which means that only you can answer it. However, I can give some examples that might help guide your work.
An example of a primary source that you might encounter in your own life is that of a news article. As this article is likely to be written by a reporter witnessing the events, it can be considered a primary source. On the other hand, an example of a secondary source would be a non-fiction book that talks about a historical event. This is because such a book would give a second-hand account of an event based on historical information.
Answer:
The World War 1 experience impacted hugely on U.S. culture, domestic politics and society. The war also resulted in an increased demand for weapons abroad. This led to increased profits and heightened productivity in the American steel industry. World War 1 ushered in an era of using chemical weapons.
Answer:
John Wilkes Booth was an actor who opposed Lincoln's policies.