Consider watching this six part video series by Amanda Haberstroh, PhD, MLIS to get more familiar with how to conduct a search.
Creating a Search: Choosing the Right Words for Your Search
Creating a Search: Using a Concept Table, Identifying Concept Groups
Creating a Search: Using a Concept Table, Identifying Related Terms and Synonyms
Creating a Search: Grouping Related Terms and Synonyms
Creating a Search: Using Boolean Operators (OR)
Creating a Search: Using Boolean Operators (AND)