This package shows you the next upcoming org appointment in your
modeline.

You can left-click on it to go to it, right-click for a menu of
actions, middle-click to temporarily hide it.

After installing, enable with:

(use-package org-upcoming-modeline
  :after org
  :config (org-upcoming-modeline-mode))

See also M-x customize-group RET org-upcoming-modeline.