You can't magically create information that's not there. I have seen some positive reviews of 'genuine fractals' for enlarging photos but I have never used it myself.
Try and print a small portion of the image at 195 dpi (2336/12) and see how it looks. That will give you an idea. If you really want/need 300 dpi, you need to reshoot with a different camera. 200 dpi will probably be ok.