I'm new with python, I've been learning for a few weeks. However now I've just changed my OS and I'm now using ubuntu and I can't run any script on my terminal. 
I made sure to have the #!/usr/bin/env python
but when I go to the terminal and type, for example python test.py
the terminal shows an error message like this 

python: can't open file 'test.py': [Errno 2] No such file or directory  

what do I do?
I must save the file in any specific folder to make it run on terminal?
Save your python file in a spot where you will be able to find it again. Then navigate to that spot using the command line (cd /home/[profile]/spot/you/saved/file) or go to that location with the file browser. If you use the latter, right click and select "Open In Terminal." When the terminal opens, type "sudo chmod +x Yourfilename." After entering your password, type "python ./Yourfilename" which will open your python file in the command line. Hope this helps!
Running Linux Mint
How to run python script on terminal (ubuntu)?