Here is my proposed Goliath change:
Ability Score Increase. Your Strength score increases by 2, and your Constitution score increases by 2.
Age. Goliaths have lifespans comparable to humans. They enter adulthood in their late teens and usually live less than a century.
Alignment. Goliath society, with its clear roles and tasks, has a strong lawful bent. The goliath sense of fairness, balanced with an emphasis on selfsufficiency and personal accountability, pushes them toward neutrality.
Size. Goliaths are between 7 and 8 feet tall and weigh between 300 and 400 pounds. Your size is Medium.
Speed. Your base walking speed is 30 feet.
Natural Athlete. You have proficiency in the Athletics skill.
Stone’s Endurance. You can focus yourself to occasionally shrug off injury. When you take damage, you can use your reaction to roll a d12. Add your Constitution modifier to the number rolled, and reduce the damage by that total. After you use this trait, you can’t use it again until you finish a short or long rest.
Powerful Build. You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift. In addition, when making Strength or Strength-based skill checks against creatures of Medium or smaller size, you have advantage.
Mountain Born. You’re acclimated to high altitude, including elevations above 20,000 feet. You’re also naturally adapted to cold climates, as described in chapter 5 of the Dungeon Master’s Guide.
Languages. You can speak, read, and write Common and Giant.