Use at least 10 peer-reviewed journal articles to support your project.
This simple search method in PubMed is recommended for most researchers. It auto maps to term variations and MeSH terms. However, if you desire, you can do much more complicated searches.
Try the filter "randomized control trial" to limit to one of the research methodologies that will work for this assignment.
For the most part, a simple string of keywords in the basic search box is the best way to search Pubmed. The auto mapping in Pubmed can be super handy. It can also be frustrating if it pulls too much irrelevant content. You can turn off auto mapping by using quotation marks or field codes. Here's an example of a complex search using quotations and some field codes.