Is there such a software that lets me hide and lock images and other stuff on my desktop?

There is an icon in the lower left corner of your screen, called "Start". Click there and you get a menu of menus. Click each item in the list and see what options you have. You don't have to memorize everything, just remember that it is there. Every program you use has a similar tools menu somewhere, although some programs conceal it. For instance, Firefox makes you right click in the upper right corner to get the toolbar menu. When you have done this procedure in every program that you use regularly, then you can claim to know how to operate a computer at the beginner level.

Select a place in your directory tree. It can be anyplace, and you must remember or record all the details to get access again. At the top of the window, click "New folder". Name it. Now right click on the folder and select "Properties". Change the status to "Hidden" and give it a password. To get into this directory you have to go to the folder where you created it and TYPE the name in the address bar. Then enter the password.

You might want to go to google.com and search "pretty good privacy" for more secure storage. I suggest that a much better plan is to buy a thumb drive to store your pictures, and lock it up somewhere.