Blender is a computer application for 3D and modelling. The software is open source and may be used freely.
More information about the software can be found at the project website www.blender.org.
Please also see Blender (software).
If you are using another computer, you can download the installation files at www.blender.org/download/.
For questions about the software itself, please contact your teacher or the project support at www.blender.org/support/.