I am new to this but from my initial project requirements, I will need to join GPS Module and RFID Module to a Raspberry Pi 4. Do the GPIO pins support the required output? Is there any guide on how to join two modules to Raspberry Pi?
Short answer YES.
The GPS module uses Serial = Yes you can do that with a Raspberry Pi
The RFID module uses SPI = Yes you can do that with a Raspberry Pi
And for the question about "How", there are a ton of tutorials on this topics that are easy to find.