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