1. join the rx/tx together on your adapter , then using the serial tool you should see what you transmit in the receive window . at least then you know your adapter is working
2. a led in series with a resistor to ground on the rx and or the tx line will flash when data is being sent.
3. read the data sheet some pic euarts need both tx and rx to be set to input .
4. most pic euarts sent inverted data , you may need to invert your signals----- read the data sheet
5. if your not using parity don't use parity defines , its probably a good idea to define bits 8 ---- read the manual
6. be aware of the flow control pins -----read data sheet