Libgdx concept and purpose of the classes

Hello,

One more newbie here :). I need help to understand how to use classes in LibGDX. I have splash screen, then main menu screen with buttons and game screen. In game screen i want to put some images. Lets say i want to change position of clicked image from start position to point B(specific position on screen).

My game class implements Screen.
Questions:
should i use sprite or actor for images?
Should i use Image or Actor class for this purpose(i saw that classes on some tutorials)

or i can finish job in my game class that implements screen?

I would appreciate if someone can explain me how to proper use LibGDX classes. Thanks