Do I have to use mySerial?

Other Hardware Sensors
1

Alright, just a quick question, in the following context, do I have to use "mySerial.available" or can it be "portOne.available"

if (mySerial.available() > 0) {
2

Assuming you refer to Software Serial or similar, it does not matter what name you assign to the instantiated object.

3

That's the code where you are assigning a name to your Software Serial Port:

SoftwareSerial mySerial(2, 3);

You can change it to anything and use that later in your code & get your output on Arduino Serial Monitor.