Which way are you driving? The B140 via Hamilton? Or via the Princess via Colac then Warrnambool?

Warrnambool has Lake Pertobe. Huge park, Cafe and a takeaway across the road on the beach side. You may be able to park at it, otherwise park up the top of the hill at Flagstaff Hill, as there are heaps of caravan parking spots there.
Botanic gardens are good as well
Port Fairy is quite nice, found a reasonable park there just down from where the fishing boats are. Sadly I think the fish and chip shop there has closed down. Otherwise Port Fairy has many cafes.