MEDLINE is the U.S. National Library of Medicine® (NLM) premier bibliographic database that contains more than 23 million references to journal articles in life sciences with a concentration on biomedicine. A distinctive feature of MEDLINE is that the records are indexed with NLM Medical Subject Headings (MeSH®).
From U.S. National Library of Medicine's fact sheet.)
This video tutorial from EBSCO demonstrates how to conduct a search in Medline Complete. Note, the demonstration is using the simple search box. SAU's Medline Complete will open to the advanced search screen. The search techniques remain the same.
This tutorial on MeSH comes from EBSCO. While it demonstrates searching MeSH in the CINAHL database, the techniques may be applied to Medline. Also, CINAHL is another medical database that will be useful to you in your research.