First, it may help you to draw the hydrogen atoms on your chemical structures. Then it should become evident why the proton NMR spectra are very similar, with the exception of the one peak you mentioned. Proton NMR provides information about the chemical environment of protons in a molecule. If they are near an electron withdrawing group (e.g., attached to a carbon that is near an oxygen atom), then they tend to be shifted to larger ppm values. The closer they are, the more they are shifted. As a very rough rule of thumb, if the proton is 2 or more carbons away, you may see very little shift. Given where hydrogens are in comparison to the carbonyl that is formed during your reaction, can you understand the proton spectra?
13C NMR in effect will provide information about the chemical environment of carbons. It is a nice complimentary tool to proton NMR, particularly for molecules that do not have protons attached at all carbon positions. Sometimes it is hard to assign carbon peaks to specific carbon nuclei in a molecule. APT 13C NMR is a technique that helps you to distinguish carbons by the number of protons that are directly attached to them, which simplifies this problem. With the proton spectra and carbon spectra, a fuller picture of the chemical structure can be obtained. For chemical transformations that result in very little difference to proton NMR spectra, the addition of specialized 13C NMR spectra can be very useful.