There are very few chances that people who bought the same theme actually keep an eye on the forums and will be able to help out; others like me, can only make an educated guess to point you in the right direction.
But all themes come with documentation, did you get the chance to read it?
Usually sliders have their own menu for management, or they are created through theme options.
Logo changing is mostly done in themes through the theme options panel as well.
Hope that helps a little.