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