You need to know some basic search techniques such as
A phrase consists of two or more words. To search for a phrase, you use quotation marks, for example, "social media". Then you get results where these words are in the same sequence and spelled the way you wrote them. If you search for social media without the quotation marks, you will get results with both these words but not necessarily connected.
Truncation is a technique that broadens your search to include various endings. To truncate you write the first part of a word followed by an asterisk*. For example, if you search for adolescen* you get results with the words adolescent , adolescence or both.
To search for synonyms and related words in the same search you use an operator called OR. For example: young OR youth OR adolescence.
All, some or at least one of the words will be included in your search result. Use OR to broaden your search.
The operator AND is used between your search terms to include all of them, for example:
young AND "social media" AND "mental health"
Use AND to narrow your search.
You can use a combination of AND and OR in a search. For example:
Most databases give you the opportunity to limit the search result by publication year, language, publication type, etc.
It is important to continually evaluate your search result. Are the hits relevant to your search question?