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