See a guide to using the library for teaching, classwork, and research during the coronavirus outbreak: https://guides.library.msstate.edu/coronavirus
To find journal articles, you will primarily use the library's online databases. In the databases, you can conduct keyword, author, title, or subject searching.
When you just have a citation:
Many authors, especially federal government employees, post versions of their articles online. So you may be able to find what you need through a Google or Google Scholar search.