thank you for confirming. please do not forget to select a positive rating as this is the only way I receive credit for my answer, thank you
this vehicle does not have electronic steering
so, if the power steering is out, then either the pump has failed, the belt has broken or come off, or the fluid is low.
if the belt is off or broken, then you might also not have a functioning water pump, so if you drive the car, it could overheat, which could cause thousands in damage.
if the fluid is low, you could damage the steering components driving it
also, driving without power steering is really not safe as most people are not strong enough to make quick turns without power assist.
as for the electronics, I would suggest you check all fuses if you have not.
it is very difficult to pinpoint an issue like this remotely, as there are many possibilities for the cause and many hands on checks are required to verify
if the fuses check out then you may have a short, loose connection, failed control module, failed ignition switch, failing alternator and / or battery. if the belt is off, then this would not drive the alternator, which can give all kinds of weird issues. also the ignition switch is a prime suspect as it could cause the battery to drain and also the weird symptoms. It would be advisable to use a bmw specialist for hands on diagnostics.
at this time I would advise that you check the condition of the drive belt and power steering fluid level, if the belt is still on and the fluid is not low, you could technically drive the car to the workshop if you can steer it and the brakes and brake lights work, but I would not advise doing so for safety reasons.
best wishes with your repairs. please let me know if you have further questions. please do not forget to click a positive rating as this is the only way I receive credit for my answer. thank you.