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