I have a lump next to my tonsil with a single hard white dot could it be tonsilitis or is it oral cancer?

Cancer unlikely: Cancer in a teen is rare. More likely is a tonsil stone. Some people have inflammatory responses by their own white blood cells in the holes (crypts) on their tonsils' surfaces... thus leading to lumps of stuff we know as tonsil stones. A primary care doctor can examine, but if medical treatment doesn't make things well enough for a patient's desires, the next option may be seeing an ENT doctor.