Welcome to the forum drn. The brains trust here is pretty good and uniquely Australian. If you have questions, ask away. A helpful crew with depth of experience.
There are yachts anchored in the Mooloola River up past the Wharf marina.
Well before attempting to enter via the Wide Bay Bar log in with VMR Tin Can Bay to get the current way points for entering. DO NOT CUT CORNERS. I would phone them the day before.
Try to time your entry for the top of a morning tide. If it is blowing 20 kts plus it could be scary and on a yacht that size it might pay to retract the keel if possible to reduce the risk of broaching.
Cheers