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