M is option key in macOS. M+RET wouldn't work in cli version, see this: https://github.com/syl20bnr/spacemacs/issues/3283

Cheatsheet

Note, some key combinations don't work in tty: https://orgmode.org/manual/TTY-keys.html#TTY-keys

• insert new TODO entry/checkbox item M-S-RET aka alt-shift-ret
• convert heading to checkbox C-c -
• convert checkbox to heading C-c *
• Update checkboxes progress C-c #
• rotate the state of the current item C-c C-t

• C-c C-j or SPC . j new journal entry

• Clock in: C-c C-x C-i
• Clock out: C-c C-x C-o
• Insert a timesheet summary: c-c c-x c-r
• Update a timesheet summary: c-c c-x c-u
• Update all timesheets: c-u c-c c-x c-u
• Custom the clock table: http://orgmode.org/manual/The-clock-table.html

• C-c [ Add current file to the list of agenda files. The file is added to the front of the list.
• C-c ] Remove current file from the list of agenda files.
• Open weekly agenda: c-c a, press L for summary
• Open daily agenda: :org-agenda-day-view
• Move day forward: M-l (Option key on macOS)
• Move day backward: M-h
• Open transient state: M-SPC (M is option key on macOS)
• C-c C-d Enter a DEADLINE date
• C-c C-s Enter a SCHEDULED date

• Next/Prev heading C-c C-n/p
• Next/Prev heading (same level): C-c C-f/b

http://orgmode.org/manual/Structure-editing.html

• New head, item or row: M-<RET> (M is Option key on macOS)
• New heading at the end of current subtree: C-RET

Update time entry: C-c C-c or C-c C-y

C-S-<up/down> (org-clock-timestamps-up/down)

On CLOCK log lines, increase/decrease both timestamps so that the clock duration keeps the same.

S-M-<up/down> (org-timestamp-up/down)

On CLOCK log lines, increase/decrease the timestamp at point and the one of the previous (or the next clock) timestamp by the same duration. For example, if you hit S-M-<up> to increase a clocked-out timestamp by five minutes, then the clocked-in timestamp of the next clock will be increased by five minutes.

ref: http://members.optusnet.com.au/~charles57/GTD/org_dates/

#+STARTUP: overview
#+STARTUP: content
#+STARTUP: showall
#+STARTUP: showeverything

http://orgmode.org/manual/Clocking-commands.html