Just to be clear ‘homing’ and ‘zeroing’ are different things. The machine will prompt you to home the machine when it first boots up and this will prevent it from crashing into the end limits. It would also throw you an error code when you load the g-code and it sees the program would exceed the limits. You can run a program without homing first but your machine will have no idea how far it can travel before it tries to run past the limits, I suspect this is what’s happening for you.
Zeroing tells the machine where your material is located, and corresponds to the zero point in your cad software.
Refer to the Homing and Zeroing sections in this post https://forum.onefinitycnc.com/t/help-my-toolpath-says-under-or-over-with-videos