My natural soil here is Florida is nothing but sand. Technically it is called Myakka Fine Sand. It is what exists in the environment we live in, which is the hardwood hammock. It does get heavily amended by leaf debris from all the deciduous trees, etc.
Sand is usually not used to enrich growing substrate because it causes the soil to compact. This seems contrary to what you would think, but it doesn;t increase drainage when added to things like peat and clay, it makes them compact more.
Things that will enrich and lighten your soil are things like perlite, fir bark, horticultural charcoal, etc. Not sand