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 self sufficiency and personal accountability, pushes them toward neutrality.
Size. Goliaths are between 7 and 8 feet tall and weigh between 280 and 340 pounds. Your size is Medium.
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.
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.