If you’re visiting Australia, in particular, Victoria, and would like to get up close to a kangaroo in the wild, then I encourage you to visit Lysterfield Lake Park in the early morning hours. Anytime from sunrise till about 9am you’ll see these beautiful animals grazing in their family groups, by the lawns, carpark, even down by the beach of the lake. Definitely on the walking tracks.
While I don’t recommend you try touching them, you could reasonably get to within a few metres of them to get a decent photo before they decide to take off. I use a 70-300mm lens most of the time so they look like I can reach out and touch them… almost!