In addition to other feats taken at 1st level, as a Goliath you may take this feat as a replacement for the Giant Ancestry feature.

Born of an Ettin bloodline — giant-kin with two heads sharing one body — you carry the will of two minds. You have uncanny mental resilience and can channel your strikes with both wills at once, though companions may sometimes wonder that you argue with yourself.

Giant Ancestry

You can use benefits a number of times equal to your Proficiency Bonus, regaining all expended uses when you finish a Long Rest.

When you use this feature, choose one of the following benefits:

• When you make a Saving Throw against an Intelligence, Wisdom, or Charisma effect, or against a spell from the Enchantment school, you can use your reaction to gain advantage.
• As both minds focus, one time when you hit with a weapon or spell attack, you can use this feature (no action required) to change the damage type to Psychic.
• When you take Psychic damage, you can use your reaction for resistance to that damage.