Just checked your Lodestone profile and see you only have MRD to lvl 31. What you should do now is go to Uldah and unlock GLD then level it to 15, return to MRD guild in Limsa and take the quest to unlock your job WAR.

The crystal will boost your needed stats and also open up quests every 5 levels to give you important skills needed for WAR, most importantly the level 30 one, Defiance.