I have a main function that has a char, I am attempting to pass a pointer to that char into a function and have it change it from A to
You have to dereference the pointer passed to setChar() in order to modify the value it points to, not the pointer argument itself.
You also have to use the character literal 'B' instead of the string literal "B" (which is a pointer to char, not a char).
void setChar(char* charToChange)
{
*charToChange = 'B';
}