There are no errors in output, yet this NPC still won't move. Any thoughts?

local Folder = game.Workspace.ScriptingStuff
local Humanoid = Folder.Zombies.Zombie.Model.Humanoid
local Destination = Folder.Destination

Humanoid:MoveTo(Destination.Position)

You can only use MoveTo() on models. So your code should look something like this:

local Folder = game.Workspace.ScriptingStuff
local Zombie = Folder.Zombies.Zombie.Model -- just make sure this is a model
local Destination = Folder.Destination

Zombie:MoveTo(Destination.Position)

Thank you very much. Although this solution is so simple, I straight up could not get an answer from anyone.

well not true, the it can be used on the humanoid too but it way more different then the Model:MoveTo() since in Model:MoveTo it positions it (and not make it move) to the vector3 given. it is used if the model does not have a “primaryPart” to position it i believe. and well in the other hand “Humanoid:MoveTo” makes the character move (or walk) to the vector3 it has been given.