I only ever get closing quotation marks in impress. I found some discussion about quotation marks in Writer , but no mention of them in Impress.
It works in Impress similar to Writer, use the (1) AutoCorrect option, or (2) insert them manually.
(1) Open Tools > AutoCorrect Options > tab Localized Options. Make sure “Replays” is checked. Open the Style&Formatting dialog and make sure, that the language is set correctly in tab Font in graphic style “Default” and in all presentation styles.
(2) Insert the quotation marks with Insert > Special Characters. In which subset you find the quotation marks depends on your language. For France they are in subset “Latin-1” for German and English they are in subset “General Punctuation”. The item Special Character is only available if the object is in edit mode and you are going to write something.