I prefer using google to search questions on Stack Overflow because they have a very good searching algorithm/AI. However, it's impossible to search for questions about stack overflow on Stack Overflow, because if you search for stack overflow it will interpret it as the website Stack Overflow rather than the subject of a stack overflow.
Example: Searching Android Activity Stack will actually result in results from stackoverflow.com containing the words "Android" and "activity" but not necessarily the word "stack".
How do I search for something about a stack overflow, or even simply the word "stack", on Stack Overflow if using google?
site:stackoverflow.com android "Activity Stack"
if you must. Searching for stack overflow errors is more tricky but I think there are only so many things to know about stacks or stack overflows and there are better resources than SO to learn about them. Just use the site's search and stackoverflow tag.