Here is the full list of all 50 Starfield achievements. It takes around 100-120 hours to unlock all of the achievements on Windows.
Eliminate 300 Creatures
Collect 20 Quantum Essence
Reach Level 50
Complete "Unearthed"
Complete "Entangled"
Complete "Legacy's End"
Complete "The Best There Is"
Join the Crimson Fleet
Craft 100 Items
Bypass 50 Digital Locks
Land on 100 Planets
Complete "Executive Level"
Complete "In Their Footsteps"
Complete "High Price to Pay"
Access 50 Computers
Complete "Further Into the Unknown"
Complete "All That Money Can Buy"
Complete "Guilty Parties"
Join Ryujin Industries
Complete "Into the Unknown"
Eliminate 300 Human Enemies
Complete "The Hammer Falls"
Complete "Surgical Strike"
Modify a Ship
Join the Freestar Rangers
Complete "A Legacy Forged"
Complete "The Devils You Know"
Reach Level 25
Visit 20 Star Systems
Build an Outpost
Complete 30 Terminal or Misc. Missions
Reach Maximum Relationship Level with a Companion
Complete 30 Activities
Reach Level 10
Join the UC Vanguard
Join Constellation
Reach Level 5
Enter Space for the First Time
Complete "One Giant Leap"
Connect 5 Outposts with Cargo Links
Produce 500 Total Resources from Outposts
Visit all Star Systems
Gather 500 Organic Resources
Gather 500 Inorganic Resources
Mod 50 Weapons
Recruit 10 Separate Companions
Collect 10 Ships
Read 20 Skill Magazines
Successfully Smuggle Contraband
Reach Level 100