Leaving a message on Project chat
You can ask any Wikidata-related question you like on Project chat. Keep in mind that it's a community-wide forum, so if you have a specific question, you may want to look to a WikiProject first. On project chat you can ask questions about how to disambiguate items correctly, clarify property usage questions, or ask about how to best reference a statement.
Beyond asking questions, reading Project chat is a great way to understand how Wikidata works. Editors discuss ways of improving processes on Wikidata, new editors ask how properties work, and debates about best practices play out here.