How do I set up livesplit for speedrunning on my PS4. I'm new to speedrunning and want to start with my favorite game that I have easy access to.

Livesplit is a program that is only available on the PC. You can't get it on a PS4.

So how do I time the run?

There are a couple ways. You can record the run first and then edit a timer afterwards

Or you can purchase a video capture card, connect that to your PS4 and PC, download a brodcasting software (OBS and XSplit are popular examples), then setup the display to capture the gameplay and Livesplit.

Thank you very much!