I have curated a Port Phillip Bay tour route that I like to give visitors to Melbourne.

Drive south from the city through the peninsula.
- Stop at the Mornington Beach Boxes for photos and a stroll on the beach. I recommend parking at Sheep Station Bakehouse across the street, and getting a proper Aussie meat pie to enjoy while you walk the beach
- Do a wine tasting along the way if you like (I am not too much into wine, so maybe browse the options here: https://morningtonpeninsulawineries....g/cellar-doors
- Take a beach detour, there are so many options, just search for what you like (sandy, rocky, cliffs, safe beaches, big waves, etc).

Overnight in Sorrento. A very pretty beach town with good restaurants and accommodation.
- You can do a swim with wild dolphins (if they feel like it) or wild seals (pretty much a guarantee) from Sorrento. https://www.moonrakercharters.com.au/

Take the car ferry to Queenscliff
- You can also do dolphin / seal swimming and/or boat cruises from here, just less frequency
- Fort Queenscliff is quite a good museum / historic site
- Also a good maritime museum here

Drive towards the Great Ocean Road
- Torquay is a nice spot to overnight or have a meal
- Jan Juc Beach is a nice easy surf spot or a great beach to relax on or swim
- Infamous Bell's Beach is worth a look

From here you can continue on the Great Ocean Road, which is well documented. But here are a couple things I like on it which don't require driving the whole way:
- The Anglesea Golf Course has a huge mob of Kangaroos (wild, but used to people). You can see them from the road that goes along the course (but past the entrance) quite easily
- In Kennet River there is a Koala Cafe, here you can buy some bird food and feed wild parrots, and if you walk up the road with a sharp eye, you can see koalas in the wild.

Or: Return to Melbourne
- Stop in Geelong. I quite like the foreshore, pier, and Wool Museum (much better than it sounds!)
- Stop at Lancemore Mansion / Werribee Park, enjoy the grounds, and make sure you see the Flying Foxes