Full list of all 23 Destiny 2 achievements worth 1,240 gamerscore. It takes around 80-100 hours to unlock all of the achievements in the base game on Xbox One.
The base game contains 13 achievements worth 1,000 Gamerscore, and there is 1 DLC pack containing 10 achievements worth 240 Gamerscore.
Acquire each Hunter subclass.
Acquire each Warlock subclass.
Complete a Nightfall strike on Grandmaster difficulty.
Complete a Nightfall strike on Master difficulty.
Collect 15 Red War exotic weapons or armor.
Encounter an Agent of the Nine somewhere in the system.
Complete 30 challenges.
Complete the "Light Reforged" quest.
Reach level 20.
Acquire each Titan subclass.
Complete a Nightfall strike.
Complete 5 Heroic Public Events.
Complete a Heroic public event.
Complete a Triumph Seal.
Complete the "Last Wish" Raid.
Collect 10 Forsaken Exotic weapons or armor.
Defeat a Forsaken Nightfall Boss.
Collect 15 Forsaken Exotic weapons or pieces of armor.
Enter the Dreaming City.
Complete the "Shattered Throne" dungeon.
Win a Gambit match.
Earn 5,000 Triumph points.
Complete a Collections Badge.