If you want to catch new folks coming in, follow #introductions and possibly to a lesser extent these days #plebchain. That is... Assuming these new folks know enough to use those hashtags.

If you are wanting assistance with literally ANYTHING, just use #asknostr. If you are asking about a specific client, you can absolutely add the client name as a hashtag, too. For instance #Amethyst, #Damus, #Primal, or #Coracle, and someone who uses that client, or even the developer(s), will respond.