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