how do i track my stolen iphone that is without an active 'find my iphone' app?

You cannot. FindMy must be active, the device powered on, and the phone must be on a network.

Here's what to do next. https://support.apple.com/en-us/HT201472

If find my iphone is off it is unfortunately not possible to track it

Just the old-fashioned way. Look around for it.

I'd lock the device and put it in lost mode as per the instructions.