I like to use the advanced search, usually something like this:
is:question closed:no answers:0
link to query
Will get you roughly ~11,000 questions where you can sort by newest or by the amount of votes. Newest may help to give you faster rep since the user is more likely to answer inquiries and mark when the correct answer is given. By votes is likely to get you the most rep if you can produce an informative answer with substance.
To add to some advanced search suggestions, you may also ignore (minus) any questions with tags you don't want to see, such as:
-[plugin-*]
remove any questions tagged as a plugin specific question.
-[multisite]
ignore any multisite questions.
- etc.
Example: is:question closed:no answers:0 -[multisite] -[plugin-*]
The reverse is also true if you want only questions that deal (are tagged) with [wp-query]
Example: is:question closed:no answers:0 [wp-query] -[plugin-*]