You can use Etar for Calendar and sync all your family stuff (calendar, contacts, files, notes, tasks, etc.) over Nextcloud. You use the DAVx5 app to connect your Nextcloud contacts and calendars to Android.
You can create an account at Murena.io to play with all of this. Murena uses Nextcloud.
For a "DeGoogled" navigation option, you use "GMaps WV" to look up addresses, and share those to OsmAnd~. You can also use Organic Maps if you prefer They both work good