The best place to start if you're looking for legal information, such as the text of court cases, is Westlaw.
The video linked below provides an introduction to using the Westlaw database. More information about using Westlaw is available on the Westlaw Training and Support page.
To find sources about the court cases, try searching for the name of the court case, e.g. Edwards v. Aguillard, on the platforms linked below. For information about these platforms, see the corresponding sections on this page.