How do you restore your icons if they disappeared?

First, if you want advice about your computer you have to give enough information to identify the answer, and the first item is the operating system.

Second, you do not "lose" your icons. You have to delete them somehow. It's hard to imagine any way to do that, but restoring them takes some technical know-how because you have to know where to find the programs. What you need is a friend who knows his way around computers to look and see what's wrong and figure out what to do about it.

After you get it fixed, find the menu system and look at everything in it. See what options you have and where to find them. Do the same in every program you have. Then you can claim to know the bare bones about how to use a computer.