Select > Color Range: Use the eyedropper and select white. Then adjust the fuzziness to include only the white and nothing else. This may or may not work depending on how well it reads the colors. Once that is done it will select everything BUT the white.
What is the currently selected layer in Photoshop called?
To name a layer, double-click the current layer name. Type a new name for the layer. Press Enter (Windows) or Return (macOS). To change a layer’s opacity, select a layer in the Layers panel and drag the Opacity slider located near the top of the Layers panel to make the layer more or less transparent.