how do I make a stl carveable when I import file it does carve the whole file
Unless something has radically changed, Easel accepts SVG and DXF files. STL files are created in 3D software. You would have to convert that to Gcode in another application and import that into Easel. I draw in Rhino3d and convert that to Gcode in Meshcam. The resultant gcode program gets imported into UGS, as I don’t use Easel. I could import it into Easel by using that option though.
I use Vectric V-Carve Desktop to make G-code toolpaths from .STL files. I use a different sender than Easel to send the tool paths to my CNC.