Does the n 0r w train stop at 30th Avenue

Yes, both trains

Both trains stop at 30th Avenue

Hi Angela, A good way to see what train is stopping at any particular stop is to use the directions feature in Google maps which will give you real time transit directions. You can also check http://web.mta.info/nyct/subway/ for maps, service changes and more.

Yes

Yes, but not Astoria blvd. It skips that station because they're doing renovation.