When you run python, or py (on Windows), then that’s just the interpreter. It expects to read a program, or if there wasn’t one to run, it will prompt you (>>> ) to type something. It is traditional to try 6*7 first.
It sounds like you are expecting it to let you edit-and-run-and-debug, but that’s a separate thing. As @MadPoet indicates, you need idle, which comes with Python (not just on Linux), or another IDE. (Or you can just use your favourite editor to make a file and run it with the python command.)
You may be able to launch idle with that command at the prompt, or py -m idlelib should do it.