The oil warning light refers to oil pressure, not level. The sending unit could be failing. The wrong oil could have been used. Or there could be internal engine damage. For the lack of power steering, the first thing is to inspect the drive belt for the pump. If the belt is broken the alternator would also quit. That will turn on the "Battery" or "Check Gauges" light and eventually it will cause the Check Engine light to turn on.

Since the Check Engine light turned on there will be a diagnostic fault code stored in the Engine Computer. If the belt broke, that code will be related to the charging system and can be erased once the belt is replaced.