I don't understand the question. Are you trying to select an object in order to place it somewhere else?
I open image say 10 x 10 duplicate layer and drag the size to say something like 50 x 50. The canvas remains 10 x 10. And still shows the original size?
drag the size to say something like 50 x 50.
If I understand correctly, you have an image 10x10 units , resolution not stipulated.
How are you "dragging"? Just what are you doing?
You open your image, and then duplicate the background layer. Now, you have 2 layers, background and background copy. OK so far. What is your next step?
Sorry the inaccuracy
When you click the image with pinting tool there are the black points in the corner. When I point any of the 4 corners, the arrow pointin diagonal towards the center appeares.. If I drag that the image gets smaller but leaving the canvas (or the original) visible on the background
You need to do everything before sending it to the printer.
Following along with your work flow, background and background copy layers, get the crop tool out of the tool box. On the tool's option bar at the top, you can enter the width & height values, or, specify "No restriction". Now is the time to drag out the crop shield to embrace what you want to retain, then commit with the green checkmark.
It's best to crop to the size of your paper stock prior to sending it to the printer, either on your home printer or at a kiosk.
For printing, it's desirable to have a resolution in the 240-300px/in range. For web work, resolution 72px/in is ok.
You're welcome. Glad to help.