I have 2 questions:
If I sketch a model in CREO 3 but I decide to rotate it or move it in my designing space, what should I do?
The idea to use in Creo Parametric modeling is that the user is creating a program that creates models.
If you want the model to change you need to change the program to allow it.
This is unlike manipulation modelers where the model depends on the user to interactively mold it.
If you attach a picture of what you want it will help.
are you talking about a sketch? then there is a rotate-resize command in the sketcher's editing group. this will let you easily rotate and resize the selected objects as a group. It is very handy, especially if you know that you can re-position that "anchor" point by holding down the right-mouse-button and dragging it.
or are you talking about a finished 3d model? often, redefining a finished model to be oriented differently relative to the default coordinate system is rather tricky.
But why even do such a thing? can it not be assembled in the proper orientation?
Well, maybe there are valid reasons; in that case the flexible modeling "move" command lets you easily transform (rotate/move) your entire model: