The big question is how it was advertised.....
Just "Topsoil" or "screened topsoil"! ????
This. The topsoil I get is advertised as screened topsoil, and it‘s free of any rocks larger than pebble sized. In fact, I have to look to find any rocks at all. I’m fortunate also that my yard is comprised pretty much only of silt loam - I never hit any rocks when digging holes, only along the fence line where I’ve dumped broken pieces of concrete and bricks to keep the dogs from digging out.
Good luck screening that stuff without a front end loader, it’s going to be a lot of work!