Savegames are saved in directory which contains few XML files that you can edit. These directories are located in:
C:\Users\YOURNAME\Documents\My Games\FarmingSimulator2017\
directory in windows 7, might be different on other windows no idea.
In the directory you saved your game, like first is "savegame1" and second is "savegame2" etc. Open the careerSavegame.xml file in text editor.
Now search for "money" and edit that value.
In the savegame dir open economy.xml file, edit the part:
<fieldOwnership> <field number="1" ownedByPlayer="false" npcIndex="1" /> etc </fieldOwnership>
ownedByPlayer false or true defines if you own the field or not.
If a new terrain start places grain into your silos and you want to empty them, then search savegame dir vehicles.xml file for fillLevel which is not 0 and set it to, well zero, like this:
fillLevel="0"
You can edit the savegame XML to add animals and their food. Open vehicles.xml and search for "Animals_sheep", "Animals_cow", "Animals_chicken", "Animals_pig" and edit the numAnimals0 value to add/remove animals, also dont forget their food levels which can be found from tipTriggerFillLevel values.