Here is the full list of all 35 A Plague Tale: Innocence achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Find all curiosities
Find all the gifts for the orphans
Find all the flowers
Fully upgrade the equipment
Stay with the captain
Play hide-and-seek
Find the tomb
Enter into the 5 alchemist carts
Complete the aiming training
Find Rodric's forge
Save the dying
Fully upgrade the sling
Find 13 curiosities
Enter through the main door
Find 6 flowers
Save a soldier
Find a lunch for Hugo
Complete all chapters
Complete chapter 16
Complete chapter 15
Complete chapter 14
Complete chapter 13
Complete chapter 12
Craft 100 ammunitions
Complete chapter 11
Complete chapter 10
Complete chapter 9
Complete chapter 8
Complete chapter 7
Complete chapter 6
Complete chapter 5
Complete chapter 4
Complete chapter 3
Complete chapter 2
Complete chapter 1