If you are referring to cinimatics, then there is a pretty good tutorial on that in the tutorial section, but I don`t know what your first langage is, so I dont know really where to direct you. Beware, its a complicated process, but it basically involved starting and finishing a cinimatic sequence using the triggers in the cininmatic and camera sections of the trigger list in the map`s trigger editor. A qucik way to leanr them is to play with them.
Missions are added by using variables and the ``quest`` triggers, also in the trigger list, such as ``Quests- create a (required/optional) quest entitled (title) using (icon) with (description). and after a certain even you use the trigger ``quest- mark last created quest (or variable quest) as completed.
-VGsatomi