We do not feel that the Earth is moving or spinning because
we are moving with it. The Earth is in orbit round the Sun but so are you and you have been
since the day that you were born. You were born moving! It is just the same as if you were
travelling in a train on a very smooth
track - you only really know that you are moving if you look out of the window or if the train
corners or stops.
You have a tendency to move in a straight line at any moment but
the gravitational pull on you due to the Earth keeps you rotating with it.
If the Earth were to suddenly stop then you would move on but for the force of friction
between your feet and the ground.
Some of the gravitational attraction provides the centripetal force to keep you rotating with
the Earth and so the net gravitational pull is slightly less at the equator than at the
poles.