How to helpEdit
Like other Wikidata editors, you're an expert! If you see something is missing fix it, document it, share it, and reach out to others to work on it with you.
This includes everything from missing items to properties that could be better defined, or ways of modeling items that could use more attention.
You bring a unique, important perspective to the Wikidata community. Whether you consider yourself a professional in a certain domain, your expertise will help improve Wikidata. Everyone has something to contribute and there are many ways to do so. Don't forget that!
Also don't forget that everyone else's perspective is important too! Disagree respectfully, strive for consensus, and never be afraid to start a conversation.