When you press the "steering wheel" button on the steering wheel and the speed in the top left corner of the screen turns blue, ACC is active, if the steering wheel symbol below turns blue as well it means that also lane centering ("auto steer", though I'd be cautious with that term) is active.
Also, it depends what you choose in the vehicle settings under MG Pilot, you have Limiter mode (basically doesn't allow you to drive faster than a preset speed, but you are in throttle and distance control otherwise), ACC or the full mode (just forgot the acronym). I don't think there is a classic "dumb cruise control" mode available.
(PS: ACC means Active Cruise Control)