For learning Morse code it is recommended that you do not try to remember dots and dashes, but remember the Morse code sounds instead. If you click on any of the highlighted letters or symbols the Morse sound will be played.
If the duration of a dot is taken to be one unit then that of a dash is three units. The space between the components of one character is one unit, between characters is three units and between words seven units (see more on Morse code timing).
The prosigns are combinations of two letters sent together with no space in between. They are indicated here using angled brackets. The other abbreviations and Q codes are sent with the normal spacing.
The definitive references for International Morse code are Recommendation ITU-R M.1677-1 which tabulates the characters but does not include most accented characters, nor some punctuation (see notes in the tables for the exceptions) and Recommendation ITU-R M.1172 which tabulates abbreviations (with only some listed here).