Hello!! I will be teaching YOU how to use structure blocks.

To get a block do /give username structure_block

Place a block in one corner of the build. Then switch it to corner and name it.
Place another block in the oppisite corner and name it the same thing. Put it on corner too.

Then place a block somewhere outside the build and name IT the same thing then hit detect. A outline of whats been copied will appear. Then hit save (If save aint there just continue.)

Place a structure block where you want to copy it then switch it to load. Name it the same thing then hit load.

Hope it helped.