IDLE, the Integrated Development Environment or IDE that ships with Python is OK but there are better alternatives out there. Before you start, you obviously have to have Python installed. The Python environment is available from the Python website; you can download the latest version for your operating system from the downloads button near the top. When you are installing Python, it is a good idea to add the python executable to the system path variable to make it easier to use python on your machine.
The first alternative IDE is a simple extension manager for IDLE called IDLEX. You can download IDLEX from the IDLEX website. It looks very similar to IDLE except that it has an extensions manager and, most importantly, allows you to clear the console - amazing!
The second alternative you can use is Thonny. Thonny is built for education and you can download the latest version from the Thonny website. The download options are at the top right. Thonny looks quite different to IDLE - it has different panels for the editor, the shell and the variables watcher plus (show view) lots of other options as well. It has a powerful debugger built in and other tools which let you manage packages and plugins.
The best way to get to grips with these alternative IDEs is to download them and have a go - what are you waiting for?