Until now you probably did 'quick & dirty' searches: you type a few words into the search bar and then press enter. That's fine for a first step in your orientation, but if you want really good results, you need to approach your literature research in a structured way. Like this:
A. you come up with a good search question
B. you find search terms for your question
C. you explore your search terms and come up with e.g. synonyms
D. you create a building block matrix with all those search terms
E. then you devise your search strategy
F. and apply effective search strategies to various search methods
Sound difficult? It might be in the beginning, but once you figure the system out, you can save a lot of time because this structure allows you to find good and reliable ( = high quality and relevant) literature.