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