Well. First off, hello to all Tenchu fans! Were a small lot, but I'm sure a dedicated one to one of the most under rated games of the entire playstation era! I am brand new to attempting speed runs. As such, I was curious as to how this works. Do we run an emulator like epsxe, and just record it all? Do I need special software that counts each level/compared by time with the world record like I've seen on twitch? Thank you so much

This is very dependant on the game you're planning to speedrun, but generally all emulators are acceptable.

OBS and Livesplit are great programs to start with when it comes to setting up a speedrun.