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