I cannot locate the file saved in terminal

Novice self learning Pythoner here.
Using macOS, saved a ‘hello world.gpy’ file in one of my folders on desktop.
Want to run this thing in terminal by command line. When keying ls it lists all the files I have in the folder, but when I access the file command line returns no such file or directory.
Do I just need to wait a little more for the system to pick this up since the file is new? It didn’t recognize the new folder a while ago either…