WavePad does not show the bit depth of the files you load, the only time you will be able to ¨SET¨ this is after you go through the ¨SAVING¨ process of the file, you will then be able to choose the bitrate of the file before saving but you will not see what was the original bitrate of that file.
You can check the bitrate of the file by right-clicking on the file before loading it into WavePad and going to ¨Properties¨ > ¨Details¨ tab, here scroll down the page to see the bitrate of the file.