Your description is rather confusing. It is not a good idea to connect your HC05 to Rx0 and Tx0 because those pins are used by Serial for communicating with the Arduino Serial Monitor.
Don't use serialEvent(). It is only triggered by data in the Serial input buffer - not by Serial1, Serial2 or Serial3. It does not do anything useful for Serial either.
Have a look at the examples in Serial Input Basics - simple reliable ways to receive data. You can create a separate function and associated variables for each Serial port.
...R