Use only one citation style per project (APA or MLA most common). Ask your teacher what style they prefer.
Use cite suggestions provided by databases when available.
Ask your teacher if the database cite suggestion is good enough, or whether you need to further check your style with a style manual (especially in technical and upper level writing courses).
Copy/paste and alphabetize citations yourself, or use a citation manager such as KnightCite if you have a large number of resources.