Problem : Cannot instance class I made.

Dear Dream.In.Code community,
I am trying to learn C# and I'm doing it by myself, with a book in one hand and the other one on the keyboard. So I decided to make a new class, that is a console calculator class( I know I can make it much simpler and I have but I want to try to make it class based, and I need all the functionalities I implemented in the code( and I hope I have done it correctly). Now my problem is that I don't know how to instance my class, or how to make it so it's usable, and if possible with user input parameters( however for now it's optional. I have included the code here:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

    public class Calculator
    {
        
            public Double operand1;
	        public Double operand2;
            public Double radijuspol;
            public Double Radijusprec;

            public Double PI = Math.PI;
	        
	 
	        public Calculator(Double num1, Double num2)
	        {
	            this.operand1 = num1;
	            this.operand2 = num2;
	        }
	 
	        public void Broj1()
	        {
	            Console.WriteLine(this.operand1);
	        }
	 
	        public void Broj2()
	        {
	            Console.WriteLine(this.operand2);
	        }
            public void radijus (Double num1)
            {
            this.radijuspol=num1;
            }
	        public void Radijus (Double num2)
            {
            this.Radijusprec=num2;
            }
	        public Double Sabiranje()
	        {
	            return this.operand1 + this.operand2;
	        }
	 
	        public Double Oduzimanje()
	        {
	            return this.operand1 - this.operand2;
	        }
	 
	        public Double Mnozenje()
	        {
	            return this.operand1 * this.operand2;
	        }
	 
	        public Double Dijeljenje()
	        {
	            return this.operand1 / this.operand2;
	        }
	 
	        public static Double Sabiranjestat(Double num1,Double num2)
	        {
	            return num1 + num2;
	        }
	 
	        public static Double Oduzimanjestat(Double num1, Double num2)
	        {
	            return num1 - num2;
	        }
	 
	        public static Double Mnozenjestat(Double num1, Double num2)
	        {
	           return num1 * num2;
	        }
	 
	        public static Double Dijeljenjestat(Double num1, Double num2)
	        {
	            return num1 / num2;
	        }
	        public static Double Povrsinakrugapoluprecnik(Double num1)
	        {
	            return Math.PI * num1 * num1;
	        }
            public static Double Povrsinakrugaprecnik(Double num2)
            {
                return (Math.PI * num2 * num2) / 4;
            }
        }

thanks in advance guys.