Although PubMed is a publicly available database, it's a good idea to enter the database by using the University Libraries' Indexes and Databases list. This will give you access to all of the full-text journals to which the Libraries subscribes while you do your searching.
The National Library of Medicine, the producer of PubMed, has a guide to help you get started as well as a series of comprehensive tutorials.
Quick Start Guide (https://www.ncbi.nlm.nih.gov/books/NBK3827/#pubmedhelp.PubMed_Quick_Start)
Search tip 1
When you use the search box on the PubMed home page, your search will be interpreted as a keyword search. Appropriate MeSH (Medical Subject Headings) terms will be added using the Boolean operator, OR. If you'd like to see what the MeSH terms are before you begin searching, you can consult the MeSH database. https://www.ncbi.nlm.nih.gov/pubmed/?otool=njrutulib
To incorporate the terms into your search, you might select Advanced search to build your search. Then you can select MeSH from the list where you see All Fields displayed and then go to Index Terms to select the subject heading you want.
Search tip 2
On the search results page, you'll see the box, Search Detail, which will tell you exactly what actions the search engine took. You can edit these actions if you wish to focus on MeSH terms only. When you're ready, just click on the Search button. You can also click on See more.... to get a larger version of your search that's easier to edit.
Search tip 3
Having second thoughts about a search you ran earlier in your current session? Do you want to review a citation you displayed previously? Look for the Recent activity box in the lower right corner of the screen and click on the action you'd like to repeat.