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