What you can see in the Photoshop Window?
Initial PS environment has the following components:
Title bar
Menu bar
Options bar: displays the options for the selected tool.
Tools palette
Other palettes

Controlling Palette
show/hide all palettes: Tab
show/hide all palettes except tools: Shift+Tab
All the palettes can be managed with Window Menu

Open an existing image
File–>Open (Ctrl+O)
(or)
Open required folder contains picturesDrag the picture into photoshop area

Each image will be opened in its own window. Many Images can be opened at a time but one can be activated.

Manage Opened Images
change between opened images: ctrl+Tab
Close current Image Window: Ctrl+W

Check the size of already saved image: Image menuImage Size
Create duplicate of opened image: Image MenuDuplicate

Adjusting Work Area
Usually designers use keyboard shortcuts and hot keys to complete their work fast. Some times the opened palettes appear clumsy. You can more work space by simply focus on one image without any distractions. This can be possible through Full Screen mode option.
There are three options to work with the current image into full screen
Standard
FullScreen with Menu bar but no title bar
FullScreen without Menu bar and title bar

The options available at the bottom of the Tools palette. You can also change between these modes by simply pressing ‘F’

Changing Magnification level of image
view image in fit in window: Ctrl+0
view image in actual size(100%): Ctrl+Alt+0

Magnifier and Hand tools are located at the bottom of the tools palette. Magnifier is used to bring the desired portion of the image to close and also to reduce the magnification. Hand tool is used to move the image across the screen to see the remaining portion of the image when it is in magnified.

magnify image from its center: Ctrl+ +
decrease magnification from center: ctrl+ –
change to zoom in tool temporarily: hold Ctrl+space and click/drag
Change to zoom out tool temporarily: hold alt+space and click
Change to Hand tool temporarily: Hold Space and drag