When you have an image saved to your computer select “File” – “Place...”
Once you place the image on or next to the artboard you can move and resize the image by activating the Selection Tool (V) in the Tools Panel. Shift-drag a corner to resize the image without distorting the proportions. When finished, release the mouse button and then the Shift key.
Click the Crop Image button in the Properties panel on the right side of the document to crop parts of an image
Drag any handle around the image to remove an unwanted portion. Click Apply in the Properties panel
To unlock something go to “Object” – “Unlock All”