Training
 

Im a level 50 fighter and i have finished all of my quests and im at 50% where should i level? Also can you tell me for level 51-55 please.

5x abyss, collapsed prison, scaffold execution ground. :) also BOD (Bonds of Darkness)... BOD gives best exp and u have/will have quests there. For 50's there are repeats so spam repeats with a good party, turn in other quests when you're stuck. The King Coll tooth quest has a horrible drop rate, so don't rely on that one too much (I think that's the repeat for level 52). I think 51 was 80 weakend ogres and 53 is 20 or 25 vivis and 100 vamp bats (look on FF Wiki for the quest list).