The bike can work without the App, just giving you resistance. You will not see a resistance value unless you use the APP. Make sure the bike is plugged in, and start pedaling. Turn the knob and the resistance will work.
You can use the App in the Freestyle area (in more sections of app) without a subscription. The bike will give you your stats without a subscription via the Freestyle rides. You can ride the Freestyle rides, and see the stats during and after the ride, but they will not be saved in the Progress Area. If you join the FitPass program, it will save to the Progress Area, providing you a history of your rides/workouts.