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