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