Sand and cement at sides of front (open) porch

Hi,

I bought a house a few months ago and only getting around to cleaning up the front of the house and I would like to clean up my front porch. Its an open porch and the sides are sand and cement and look very dark (grey) along with my black front door. I would like to brighten up the inside of the porch and wanted to paint it white but because of the sand and cement I think that it would look very rough and I would like it to look smooth.

Is is possible to plaster it and then paint it or is this not possible because its sand and cement?

Would appreciate any advice.

Thanks