Can't launch Python Idle

It’s my financial analysis task, I was required to draw a graph of return by using python. It’s first time I use Python.

I download the latest vision of Python, 3.8.3, from official website. I have added the path, and successfully added matplotlib. (the tool to draw graph?)

Then I found that I can’t or don’t know how to launch the idle.
I have been tried several ways, (-m idlelib, print(“Hello, from Idle”). AND I did add the path when I’m installing.