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.
Encounter an Agent of the Nine somewhere in the system.
Collect 15 Red War exotic weapons or armor.
Complete Introduction: Crucible.
Acquire each Titan subclass.
Complete a Flashpoint on Earth, Titan, Nessus, or Io.
Acquire each Warlock subclass.
Acquire each Hunter subclass.
Complete a Nightfall strike.
Reach level 20.
Complete a Heroic public event.
Complete 30 challenges.
Complete the Leviathan raid.
Complete the Leviathan raid on Prestige difficulty.
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.
Pursue Uldren and the Fanatic to the Watchtower, and finish what you started.
Complete the "Last Wish" Raid.