Here is the full list of all 50 Starfield achievements. It takes around 100-120 hours to unlock all of the achievements on Windows.
Gather 500 Organic Resources
Collect 10 Ships
Eliminate 300 Creatures
Complete "Executive Level"
Complete "The Hammer Falls"
Complete "Surgical Strike"
Gather 500 Inorganic Resources
Complete "Legacy's End"
Complete "A Legacy Forged"
Land on 100 Planets
Complete "The Best There Is"
Visit all Star Systems
Connect 5 Outposts with Cargo Links
Recruit 10 Separate Companions
Access 50 Computers
Read 20 Skill Magazines
Complete "The Devils You Know"
Join the Crimson Fleet
Join the UC Vanguard
Mod 50 Weapons
Complete "Guilty Parties"
Join the Freestar Rangers
Bypass 50 Digital Locks
Join Ryujin Industries
Eliminate 300 Human Enemies
Collect 20 Quantum Essence
Complete 30 Terminal or Misc. Missions
Successfully Smuggle Contraband
Reach Level 100
Complete "One Giant Leap"
Reach Maximum Relationship Level with a Companion
Complete 30 Activities
Complete "Unearthed"
Complete "Entangled"
Complete "In Their Footsteps"
Complete "High Price to Pay"
Complete "Further Into the Unknown"
Complete "All That Money Can Buy"
Complete "Into the Unknown"
Reach Level 50
Reach Level 25
Produce 500 Total Resources from Outposts
Craft 100 Items
Visit 20 Star Systems
Modify a Ship
Reach Level 10
Build an Outpost
Reach Level 5
Join Constellation
Enter Space for the First Time