Hi Ludmilla,
1. It should be fine, but you need to be running macOS 10.14 (Mojave) or 10.15 (Catalina) or 11 (Big Sur). You might find it a little tight to work with a 128GB hard drive (if it is the lower spec model), so an external SSD would be a useful purchase.
2. The boxed version comes on a DVD. Therefore you will need to buy an external DVD drive to install it directly from the DVD onto the MacBook Air. The Apple Super Drive is nice, but expensive. There are other cheaper Mac-compatible DVD drives out there. Alternatively, if you have access to a computer with a DVD drive you could copy the installation files from the DVD to a USB storage stick and install it from there. Another (easier and cheaper) option would be to download the free trial version from the Adobe website and then convert that into a fully registered copy by entering the serial number that is on the back of the DVD case. Instructions for doing this are here:
Convert a trial version into a full version
Hope that helps 🙂