I was thinking I would have a smaller run area attached to the coop and then have a big area they can roam around which will be moveable.
A mobile tractor-run is a nice accessory, but usually proves less than practical to use every single day without fail no matter what else is happening.

Your permanent run needs to be big enough for all your birds full-time, which should be a minimum of 10 square feet per chicken.
Yes, it is metal sheeting. What’s the best way to insulate?
The most critical thing is to ventilate it. If I'm doing the climate zone conversion between US and Australia correctly, you have hot summers and moderate winters with temperatures rarely dropping below freezing?
If it were me, I'd take 6-12 inches (15-30cm?), of the siding off the short wall and replace it with wire, and build a mainly-wire wall to fill in the tall side. Then I'd open large triangles on the sides directly under the roof at the highest point and fill that with wire.
That will allow constant airflow in the optimal, above-the-birds'-head position.
Chickens are notorious for eating foamboard insulation, so it can only be used on the roof and when covered by something impervious to chicken beaks. If you search these boards for metal shed conversions you'll be able to see how different people handled the problem.
Good luck with your project!