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 Titan subclass.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Complete a Nightfall strike.
Complete 30 challenges.
Complete the Leviathan raid on Prestige difficulty.
Acquire each Hunter subclass.
Complete Introduction: Crucible.
Complete a Heroic public event.
Collect 15 Red War exotic weapons or armor.
Complete the Leviathan raid.
Encounter an Agent of the Nine somewhere in the system.
Reach level 20.
Acquire each Warlock subclass.
Earn 5,000 Triumph points.
Win a Gambit match.
Pursue Uldren and the Fanatic to the Watchtower, and finish what you started.
Collect 10 Forsaken Exotic weapons or armor.
Complete a Triumph Seal.
Complete a Collections Badge.
Enter the Dreaming City.
Complete a Forsaken Exotic Quest.
Defeat a Forsaken Nightfall Boss.
Complete the "Last Wish" Raid.