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