Pick one: Escape the Horde — opportunity attacks against you are made with disadvantage; Multiattack Defense — when a creature hits you with an attack, you gain a +4 bonus to AC against all subsequent attacks made by that creature for the rest of the turn; or Steel Will — you have advantage on saving throws against being frightened.
RollQuest ships the D&D 2014 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.