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