Some oil may have leaked into the tubing, since it sat for an extended amount of time allow the unit to stand upright for 24 to 48 hrs to allow oil to level out or you may blow the valve reeds inside the compressor, Should be fine

Of course, no oil could possibly leak out of the compressor, because it is hermetically sealed.

As long as no oil leaked from the compressor (motor), it will be fine. But it should set the right way for a day before you turn it on.

Turn it on.If cold air comes out it's O.K.

my son accidently set stored air conditioner standing up so coils were on bottom. we set it back down right way but it was all winter like that. Is the air conditioner any good now? I don't dare to try it!