What to do about these check engine codes?

[Chiketkd]

The guy at AutoZone ran my codes on a generic OBD II scanner and I looked them up tonight to figure out what they meant:

P0325 - Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)

P0748 - Pressure Control Solenoid Electrical (transmission)

I ordered 6 spark plugs and a knock sensor today from SubyPartsGirl at Langston Subaru. From my understanding, bank 1 is the right bank of cylinders on the EG33 engine. That should take care of that error code...

Not sure what to do about the second code. It's not the malfunction code (P0745), so could it be caused by an electrical malfunction somewhere in the circuitry? Would I need to replace the entire solenoid? Would it be best to get my Subaru Dealer to look at it or is there something I can do on my own? Do I run the risk of ruining my transmission?

Thanks!

Chike