Alright so this is a super broad question, because of that I am going to assume you are new to graphics programming and/or c++. So, first of all you need to decide what type of graphics you are going to use (2d, or 3d?) Then, you need to decide if you want speed or simplicity. Because of your experience, I am going to assume simply 2d graphics, to start. So use a library know as SDL. Follow the tutorials on this website http://lazyfoo.net/SDL_tutorials/index.php. Also, read these articles.
alright, I am not sure what the BGI library is, but if you followed the first tutorial on the first link I posted you should have SDL set up. To confirm, run this program and return with the results.