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