which 3d software should i learn for 3d printing —

Founded which 3d software should i learn for 3d printing models & stl files for printing
Rossi RS22 Wombat
MortalWombat
Simple optics kit
PhysicsLabTech
Zweebrigger Luiche
ChaymberCrafts
Monument to Victor Hugo
Scan The World
Medusas Head
WattsGallery