Biology

Using a Database that intentionally indexes the scientific literature is your best bet for getting started -- even if you just want a few articles! 

Sources like Google Scholar - or AI tools like Semantic Scholar or Consensus cannot see a large % of the Scientific literature - it just is not on the Public Internet.  So starting with a scientific database is your best chance of finding a really good article on your topic.  Use Google Scholar and AI tools to supplement syour searching - they often find additional things - but start with a database to give yourself the best chance of getting something good on your topic. 

If you want to catch a trout your best bet is to start with the stream that has the highest percentage of trout - not one that may have more fish, but not as many trout.

PubMed - Pubmed is an index created & updated daily by the National Library of Medicine.  It indexes all scientific literature related to Human Biology and Health.  It defines Human Biology &  Health broadly to include anything that is related to humans or has an impact on human health.   So, it includes studies that use animal models, studies of plants as they effect human health or are used in medicine, and anything on the genetic or molecular level in any organism.

Web of Science - This is an index to the top scholarly journal literature in all subject areas.  It has strong coverage in Biology.  It is the largest index for non-human biology - so for animal and plant biology. 

In addition to indexing articles by keyword and topic, it allows you to take a known, relevant paper and find other paper related to it.  You can find more recent papers that cite the known paper,  as well as find articles related to it through shared citations.