Here is the full list of all 23 Farming Simulator 19 achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Harvest 100 hectares
Sow 100 hectares
Breed 20 cows
Breed 30 sheep
Fertilize 100 hectares
Cultivate 100 hectares
Complete 50 missions
Complete 100 missions
Breed 50 pigs
Cut down 25 trees
Breed 100 chickens
Cultivate 10 hectares
Cultivate 1 hectare
Own a bank account with 10 million ingame money
Fertilize 10 hectares
Sow 10 hectares
Harvest 10 hectares
Reach 10 hours of playing time in a single savegame
Complete 1 mission
Cut down 1 tree
Fertilize 1 hectare
Sow 1 hectare
Harvest 1 hectare