I searched and viewed similar questions on here but still am very confused. Is it because of the observer's inertia? If so, shouldn't we feel a 'push' towards the point where we are actually accelerating?

Also, why would a small rock on a rotating disk be pushed towards the outside? The only force acting is inwards so why would it go outwards? It makes no sense to me. I appreciate your help truly. Sorry I am an amateur and not an expert.