There are different ways you can support Geany users. Yes, even supporting users is a contribution to the Geany project.
You can subscribe to the Geany-users mailing list and answer questions, give hints to people who write there and so on.
You can also surf through the bugs reported at the Github issue tracker and see if you maybe can help users. Some issues reported are not actually bugs and maybe can be solved with your help.
There is a group for Geany on identi.ca. It is not that frequently messaged yet, but sometimes there are users who are asking questions concerning Geany. If you are already registered on identi.ca, feel free to join us there and help users or point them to our mailing lists or IRC channels.
At the present we don't know that many users who speak the same language, except English and German. If you like to see a mailing list or an IRC channel for Geany in your language, feel free to contact us so we can discuss this.