For open source and/or free EDA tools, KiCad is highly recommended. It's a powerful tool for creating complex digital boards and has a lot of community support. For creating footprints, you might want to use FreeCAD with some effort but Solvespace can be a simpler alternative for 2D drawings. Be aware that FreeCAD is improving, but for more advanced design tasks like injection molding, some prefer Fusion 360.