COSY is a 2D NMR experiment that identifies proton-proton coupling. A proton spectrum is observed along both the x-axis and the y-axis. The 2D data is shown as a contour map where peaks identify proton-proton coupling. The matrix diagonal also shows the 1D spectrum. The useful feature on the 2D spectrum are the cross peaks (not along the diagonal) which show which protons are coupled through bonds. These protons are usually located on adjacent carbons. This spectrum shows how the molecule is connected.
Go through the COSY Spectrum and identify which protons are coupled. Combine this information with the HETCOR spectrum to piece together the structure of the unknown.