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