You don’t create designs in Cura. All of the critical dimensions (nozzle size, layer heights, etc.) are in mm across the 3D printing community.
where other units matter is in design software, like Fusion 360, Freecad, or TinkerCad, to name a few.
Those design systems allow you to design in whatever units are best for you (though if you design in inches and enter a dimension as 15/64”, it will show as the decimal equivalent 0.234375”.
In that same software simply set the STL export units to mm (STL files are dimensionless).
And, BTW, I am also in the US, and grew up on inches & feet. But I do 99%of my designing in metric.