I have a shield and inside there is a white border, I would like to delete the white inside border and have the background show though but I can't seem to "intersect" just the white border, I was able to do it with my two letters, but can't seem to figure how to do it with the white border

The red part of your logo is a single shape with red stroke and red fill. The white outline is a white stroke with no fill. You need filled shapes with no stroke.

Select the red shape and change the stroke colour to make this obvious then [Path > Stroke to Path]. This yields a group of two filled shapes with no stroke. [Object > Ungroup] then [Path > Union] to create a single shape with no stroke but the same outline as the original.

Now change the white stroke to a filled path with [Path > Stroke to Path]. Select the new white-filled shape and the lower red-filled shape then [Path > Exclusion] to delete the intersecting area.

The solution depends if it's vector or raster. If vector, just use bucket with a little expansion, then path > Union

If raster, just the Trace bitmap and it will be automatically "removed"

@Paddy_CAD

thanks so much this worked perfectly!!