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