Yes,between the rim and tire.
In standard cars is it simply compressed air. The same mixture we breathe.
No, you need the tires with the air in them to tow it.
they are filled up with regular air that our tires use but some cheaters in monster truck racing fill their tires up with water to make sure they land on all fours.
The purpose of an air compressor is to air up tires. This can be bike tires but also car tires. Because it is a small model, it takes some time to fill a car tire, but it works.
An air compressor
It's just regular air.
Check the air pressure in the tires.
Fiction: between the tires and the road. the car with the air in the drivetrain
Owner's manuals usually recommend to check the tires' air pressure weekly.
It shouldn't. There is something wrong with your tires. Probably a leak
Yes, the heat causes the air to expand in the tires. Conversely, the cold air in winter reduces tire pressure.
Most tires are supported by air pressure alone, not the tire, the tire controls things but is a casing to hold the air that hold the car up. There are tires called run flat that can work with out air pressure for a little while. In history there were solid rubber tires that did not require air at all, they were terrible.