Freecad is an open source CAD program to create your own designs or drawing in 2D or 3D environment. You can download it, if you want to try. I have different video tutorials to learn how to use freecad.
This technical drawing can be used in CAD programs to practice.
Part Design video tutorial includes
Creating constraints and dimensions in FreeCAD
-How to use constrain lock
-Mirroring parts in part design
-Creating additive pipe in FreeCAD
-How to change position of sketch in FreeCAD
Video tutorial below
