The best way to find primary sources for an assignment is to consult with a librarian at the reference desk. Often, students bring their assignments to the reference desk and work one on one with a librarian to find the right primary source documents.
There are a number of resources for primary source documents in the DVC library. If you run a keyword search for primary source, you will get an overview of resources that contain primary sources. The trick is finding the primary sources that are right for your assignment. You can add keywords-- "primary source history" or "primary source gulf war"-- to narrow your search.
In addition to print sources, there are ebooks and databases with primary sources documents. For example, History Reference Center contains "57,000 historical documents".
Again, the best place to start is the DVC library reference desk. Good luck with your search!