All right gamrConnect, we're going to play Zelda games together!

[Kenology]

Fab_GS said:

About Majora's Mask:-
  Is there anything I should know about before starting (e.g. missable stuff ...etc)?

Please without spoilers

Only one missable treasure chest in the game.  The very beginning of the game, prior to reaching Clock Town, there's a small chest on a deku flower I believe that contains Deku Nuts.  If you miss those, you miss them FOREVER!  That's the only thing though, to my knowledge.