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