I need help with object change. Like what button do this?
What do you mean by object change? Do you want a button that cycles through different objects in a scene??
It is a little unclear what you mean. Maybe your looking for edit mode? Press tab to enter it.
I mean: i have a box and now i make plate and i want change my box.
how i get that box selected again?
Right click to select.
Well, I think that before you model, have you checked out the wiki for the blender basics?
Here is a link to a very useful resource
http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro
Other than that, it sounds like you are in edit mode and you want to get into object mode, to select you cube. Press the tab button to switch between these two modes.
However if you just wish to select a face then you need to be in edit mode, the choose the selection mode from points to faces, then right chick (I think, it is all to automatic for me now) then your face should change to a pink color then you can scaleor what ever you wish.
But I do recommend before using a program to read the basics of using it first. Using a 3d program vs. 2d (photoshop/Gimp) could be compared flying a 747 vs. driving a car, one you can pick up quickly the other takes time and hard work… I suggest though, read the above link to get the help you need!:yes:
You can download a quick start sheet to help as well
http://wiki.blender.org/index.php/QuickStart
That should give you some help! Good luck. Show us a render when your finished! And cherish the moment!