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