I'm trying to learn how to use org-mode using the org manual and videos from youtube. One of the things I'm learning is opening agenda view to visually sort todo tags and deadlines. Usually, the keystroke C-c a calls agenda view but for some reason, C-c a is undefined. Unless I'm typing the stroke wrong(I know that C-c a is not C-c C-a), I don't know why it's undefined.
As a workaround, I just use menu bar > org > agenda command button. Not exactly a keystroke but not convenient as I'm learning orgmode.