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