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