Fuzz starting location depends on how aggressively we want it to expand in the first few posts. Put it in a desert and it could be centuries before it makes its way out unaided. Put it in a rainforest and it'll explode, giving it easy access to new territory and resources.

E: Also preferably not on an island. Short of assimilating the surface of an entire strait, fuzz has no way to cross seawater.