Simple c++ calculator, problems with loops?

[nonsatisscire]

k

[spaggy]

it's also suppose to be able to clear all data if you enter "C" and ask for a new first number

Easiest thing would be to store the last result in a variable and use a boolean to tell whether you should use the last result or ask for a new first number. If true set a to the variable storing the last result otherwise ask for a number.

My other problems are the calculator breaking when I enter random numbers into the operator

That's a bit vague. What numbers and how exactly does it break? Does the program crash or does it return incorrect results?

I also can't figure out a loop to return to asking for a new operator if this happens (or if you divide by zero)

bool validOperator(char op) {...}
....
do
{
  cin >> operator;
}
while(!validOperator(operator))