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