Full list of all 23 Destiny 2 achievements. It takes around 200 hours to unlock all of the achievements in the base game on Windows.
The base game contains 13 achievements, and there is 1 DLC pack containing 10 achievements.
Acquire each Hunter subclass.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Complete the Leviathan raid.
Complete Introduction: Crucible.
Acquire each Warlock subclass.
Collect 15 Red War exotic weapons or armor.
Complete the Leviathan raid on Prestige difficulty.
Complete a Heroic public event.
Complete a Nightfall strike.
Complete 30 challenges.
Encounter an Agent of the Nine somewhere in the system.
Reach level 20.
Acquire each Titan subclass.
Complete the "Last Wish" Raid.
Pursue Uldren and the Fanatic to the Watchtower, and finish what you started.
Earn 5,000 Triumph points.
Collect 10 Forsaken Exotic weapons or armor.
Complete a Triumph Seal.
Complete a Collections Badge.
Enter the Dreaming City.
Complete a Forsaken Exotic Quest.
Win a Gambit match.
Defeat a Forsaken Nightfall Boss.