If you're being asked to cite something by an instructor in English, they're likely asking you to use MLA style. Hover over the "Citing Sources" tab to see a detailed page just for MLA style.
See the other boxes on this page for help generating citations in databases and managing citations.
Part of researching is having a strategy on how to manage all these resources/citations you've found. You can use a citation management tool like Zotero to organize citations to sources, collect digital files such as full-text PDFs, and cite sources automatically when writing papers.