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