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