What is the frequency of the pulses ? As the RPi is not a real time operating system it may not be able to accurately read and report on the pulses (as well as do everything esle you have in mind) in real time.
You may be better off using an external device such as an arduino or an ESP32 to capture this info and send that to the PI
I assume you want to do all this in realtime so i would start with something simple in the native NR dashboard - there are plenty of gauge modules etc in there.
Craig
