You will find these under Insert › Special Character. If you need a particular character or even a complete string of characters very often, say “[…]”, and don’t want to keep on typing out the sequence, you can mark it once, go to Tools › AutoCorrect Options and type in on the left hand side under Replace a shortcut such as “xxx”. Then press New and confirm with OK. Now every time you write xxx followed by a space the programme will automatically write […] for you.
The list of replacements you just used to do this contains lots of standard replacements, e.g. two short dashes will be replaced by one long one and three dots by an ellipsis.