For an informative YouTube video on using the Microsoft Word "References" tab, you might try:
"How to Use the References Tab in Word" by Katie Kotynski.
(Microsoft did not appear to have any of their own.)
The following sources will provide you with the basics in using APA format.
APA Formatting and Style Guide from Purdue's Online Writing Lab. Note especially the page on in-text citations to avoid plagiarism.
APA Style: Style and Grammar Guidelines from the American Psychological Association includes information about everything from writing without bias to citing electronic resources.
Tutorial: APA Citations 7th Edition
Quiz: APA Citations 7th Edition