If you want to install IDLE, open this link: https://www.python.org/downloads/release/python-383/
Scroll down until you find "Files" table.
If you are using Windows, then give attention for versions, which start with "Windows x86", NOT "Windows x86-64".
Then you should end up in 3 options:
... embeddable zip file
... executable installer
... web-based installer
The last 3 options only affect how IDLE is installed, I would choose "...executable installer".