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