Air bikes work thanks to air resistance. Their main component is a large fan/flywheel. You can set it in motion by moving the pedals and handlebars. With this type of exercise bike, there is no option of adjusting resistance levels.
The faster you move, the higher is the level of resistance. Due to this, air bikes are mostly designed for challenging high-intensity training. They are usually not well suited for beginners.
If you’ve never tried an air bike before, you’ll likely need some time to get adjusted to it.