If something is in neither A or B where does it go on the venn diagram?

It goes outside the sets of A and B (the overlapping circles), but stays in the Venn diagram (within the box surrounding the Venn diagram)

This event would be placed outside of the circles.

A Venn diagram gives a pictorial representation and relationship amongst sets. The entire 'space' depicted by a Venn diagram is referred to as the "Universal Set" which has all sets in context as subsets. 

In certain instances, the union of all sets depicted equals the Universal Set. In this case, an element must belong to at least one of the sets depicted.  

However, in some cases, the union of all sets depicted by the Venn diagram does not equal the Universal Set. This means that there are elements that are in the Universal Set but not in any of the other sets!

To answer your question, the latter scenario is pertinent. If the Universal Set consists only of sets A and B (asides from itself and the empty set), and "something" is neither in A nor B, then that "something" is in the Universal set and not in the union of A and B. This means the "something" is in the complement of the union of A and B is in the Universal Set. Pictorially, the "something" is put outside of the plane figures representing A, B but within the Universal Set.

It goes outside the Venn diagram.

Outside the circles of the Venn diagram

you can have it floating out-with the diagram itself

On the outside of the circles

It goes outside the venn diagram.

It goes on the outside of the vent diagram but still inside the rectangle box

If something is neither in set A nor in set B, it would be placed outside the overlapping region of the Venn diagram, typically in the area outside both circles representing sets A and B. This area is often referred to as the complement of the union of sets A and B.

The something will be outside the circles of A and B but will still be in the universal set.

It will sit outside the main Venn diagram (outside of the circles) but still within the outer boundary.

In the area that is outside of both A and B.

Outside both sets A and B

If a element (say x) is neither in A nor in B for any universal set (say X), then "x" will goes into (AuB)' . And as (AuB)' = X - (AuB)