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