NNabla's tutorials are provided as Jupyter Notebooks where you can run the code step-by-step.
On many Linux (probably on Windows), Jupyter can be easily installed using pip by:
pip install ipython<=5 # IPython>=6 is not supported in Python<=3.3. pip install jupyter
You can run Jupyter server on your terminal on this folder.
Then, follow the instruction printed on your terminal to connect the server on your browser.
.ipynb files to start tutorials.