A wallaby is smaller, i’d say about 2/3rds typically. There can be some absolute unit Kangaroos, about as tall as me and there are videos of humans and kangaroos punching on, and the roo’s will punch on with other roos too. A wallaby might come up to my waist.

I can tell the differences by looking at the faces. The kangaroos nose seems longer and wider where the wallaby’s is shaped to a point. i dont remember seeing any around canberra

Kangaroos usually travel in a mob of about 5-15 with a dominant male and lots of females and joeys but you can catch them alone. They’ll usually hop along if you get too close for comfort.

Here’s a close up of a wallaby Copied under creative commons licence that requires attribution Souce:- https://en.wikipedia.org/wiki/Wallaby#/media/File:Swamp-Wallaby-Feeding-2,-Vic,-Jan.2008.jpg