You gotta love walmart.
The camera you bought cannot change lenses. And even if it could, I'm quite sure that Canon does not manufacture lenses for Sonys.
Actually, I would return everything and go to a reputable camera shop, or for pity's sake, do some research as to what you need online.
You seem smart. what do I need online?
thanks for your help. i'll take the sony back to walmart like you recommended. The canon 75-300 is the cheaper one anyway..glad that will do it for me.