The technical scientific name for the shape of the earth which is generally accepted by the scientific community is
Oblaite Spheroid
The earth is not round nor is it flat or pure sphere it is an oblate spheroid. however if you were to either reduce the size of the earth to that of a billiard ball or alternatively increase the size of a billiard ball to that of the earth you would find that even for all its imperfections the earth is actually closer to a perfect sphere than anything man can make. also it would be much Smoother. the planet sized billiard ball would have mountain ranges 100's of times taller than our highest and valleys much lower than our lowest.
Why things, i assume you mean cities and such, are not round is that a sphere or spheroid cannot be divided on the surface or otherwise by spheres or circles without intersecting them there would always be some space where the curves pull away from each other. you could put a smaller sphere in the empty space but that would only cause the spaces remaining to be smaller and more numerous down to infinity. unless you overlap the spheres /circles but then they aren't circles anymore and it would be a waste of space.
That all is assuming the world were in fact perfectly smooth which it isn't given things like topography geography and the like. spheres are not the most efficient shapes on earth. at least not for all applications in fact they can sometimes be the least efficient.
Now some places are and or were circularly built around a central point however usually this was not an economically/ financially/ geophysical feasible option. again for reasons like coastlines rivers mountains etc.
As for the bible saying the earth is flat that isn't true and he needs to read his bible more though he is correct the sun and the rest of the universe does revolve around the earth that at least i believe is biblical though i cant off the top of my head remember exactly where i think not in genesis though