Science is, at its heart, a collaborative endeavour. No scientist ever works alone, especially in the modern times we live in. As such, all scientists share ideas and information in one way or another. Information is our currency: we trade it, share it, and make it grow. This also means that giving credit to others for their ideas and information is a vitally important part of science, not to mention academic life and the Open Science movement. Again, you will learn more about Open Science and how it works next week, in the asynchronous material of Lab 3.
For your written work, every time you mention an item of information or any idea that is not your own, the source must be credited in the text. This refers not only to published material but can also include personal communications from colleagues and professors. In scientific writing, we avoid using direct quotations and footnotes wherever possible. We do not copy verbatim from our sources - i.e. copy & paste. Instead, put the source away when you write, so that you naturally rephrase the material into your own words. Finally, acknowledge the source using the appropriate style and format for the work you're trying to cite.
While many different formats exist for citing your sources, for the purposes of this project the APA 7th edition reference and citation style is to be followed. The Procedures and Guidelines: APA Citations has a quick reference guide and other resources that you can follow up with.