Always start with "Advanced Search"
It is a bit complex but it's worthwhile. You will have plenty of options to limit (focus) your results. Note the initial choices (1st picture below):
Enter your search terms. Do not be too specific - one or two words would suffice to begin with. (Have you watched "Finding search terms" video?)
Note that search results bring more options on the left side (2nd picture below) - "Available online", "Peer-reviewed", etc. Note the number of results - an indictator to broaden or narrow your search.