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