PICAXE 8 Pin Proto Kit
They are both plastic film capacitors - the 100nF which should be placed on C1.

If by "extra capacitor holes" you are referring to the + and - holes at the bottom right, they are likely to be for an optional electroltyic to provide some bulk capacitance for the power input.

It's quite common for parts to be substituted in these kits, so you maybe have a ceramic 100nF instead of the mentioned plastic film capacitor (they will both work fine)
If yours looks a bit like one of these it's a ceramic: