FreeCAD features tools similar to CATIA, Creo, Autodesk Inventor, SolidWorks or Solid Edge, and therefore also falls into the category of Mechanical computer-aided design (MCAD), PLM, CAx and CAE. It is intended to be a feature-based parametric modeler with a modular software architecture, which makes it easy to provide additional functionality without modifying the core system. As with many modern 3D CAD modelers, it will have a 2D component in order to extract design details from the 3D model to create 2D production drawings, but direct 2D drawing (like AutoCAD LT) is not the focus, neither are animation or organic shapes (like Blender, Maya, 3ds Max or Cinema 4D), although, thanks to its wide adaptability, FreeCAD might become useful in a much broader area than its current focus. For more information visit the FreeCAD Information page.
1.) Update System.
You should first be sure that your system is up to date. Open your Terminal (CTRL+ALT+t) and use this command, followed by your password.
$ sudo apt-get update && sudo apt-get upgrade