Yes, JPEG can be imported into Photoshop. However, you will need to set up a preference in Photoshop for JPEG import.
Photoshop allows you to import files in a variety of formats, including PNG. To import a PNG file, choose File > Import > PNG.
Photoshop offers a number of ways to resize and select an image. You can use the Size drop-down menu to choose how big the image will be when it is displayed, or you can use the Selection tool to select a specific area of the image.