How do I find a word in all my files in Pycharm

On the main menu, choose Edit | Find | Find in Path, or press:

Windows or Linux: Ctrl + Shift + F

Mac: ⇧ + ⌘ + F

More info here

If you look at the "project files" tool window, you can right click a directory and choose "find in path".

Actually, you should try double shift, it's search everywhere.