Here is the full list of all 13 LEGO Builder's Journey achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Journey complete
Went back home
Imagined a way out of the dark
Broke free from the machine
Made your way up from the depth
Made your way through the danger
Cleared the puzzles
Found a way in the dark
Played with your new friend
Went on an adventure
Completed the hike
Learned to climb
Learned the basics