If you don't have a particular topic in mind that you are searching for, then you can simply choose an issue of the journal from the Journal Archive ("All Issues") and scan the article titles to see what catches your interest. I'd recommend starting with the most recent issue. This is a great way to figure out how to identify a topic you find interesting.
If you have a topic in mind, many journals will have a "search within" function. It may be called something different depending on the publisher. Simply type in a word or two that captures the name of your topic, then search.
To access a journal, click the link. If you are off campus, you may be asked to authenticate with your PSU username and password. If you would like to search for a different publication, use the E-Journals search found in the "Find" box on the library homepage.