Hello and welcome to JustAnswer!
It sounds like the transmission is in limp-in, which would give you only third or third and fourth gears.
The P0129 is pretty surely being set by a bad MAP sensor, which is on the front of the intake. It reports intake vacuum to the powertrain control module, when the key is initially turned on or at wide open throttle the PCM takes a barometric pressure reading from it. P0129 sets when the barometric pressure is out of a possible range, this code set with no other MAP electrical codes pretty much guarantees a bad sensor.
The MAP sensor couldn't cause limp in but may cause driveability symptoms mimicking it. I'd go ahead and replace the MAP sensor first and see how it does.
If it still won't shift then the first thing that will need to be done is read the fault codes from the trans controller. If it's in limp-in then there will be codes stored in the TCM and diagnosing the problem will first require knowing what codes have set.