OBDII Code P0348: Camshaft Position Sensor A

You have at least two of those sensors, right? So, swap them, and when the error moves with them, it's the sensor, otherwise cabeling / ECU.

About replacing both sensors:

For most motors, the camshaft sensor is not essential. Finally, a 4stroke motor needs two revolutions for a complete cycle, and while the crankshaft sensor gives precise information about the angle of the crankshaft, it doesn't know if it's the first or second revolution. This information is taken from the camshaft sensor during the first revolution when starting the motor. Without that sensor, the motor has to find that out by other means, which is a little more difficult. As consequence, starting the motor is a bit harder, and misfires might occur, but once the motor is running, crankshaft sensor information is sufficient.
The camshaft sensor might be more important for motors with variable camshaft timing.

So, the sensor is not THAT important, and usually quite easy to replace. Replacing just one is fine. On the other side, they are not expensive, replacing both is not a big deal.

I would check the wires and connector before spending too much money.

Have you got a friendly garage / mechanic who might have a spare to "test" with?

Also, if it is the sensor then check out buying a quality one if the rest of the vehicle is good...