If your Rev would turn on but not start. Don’t worry, your issue can be fixed easily.
Turn it off, don’t move it, let it sit for a minute and then turn it on. Without moving it, slowly accelerate to start.
The Rev has a safety feature where it cannot accelerate when it is in motion while you turn it on. It could be that you moved it a bit while starting it up. Let it sit for a minute, then turn it on while not moving the wheels.