Have some questions about OOP code

Hi,

I'm trying things in OOP. I have three questions:
1) what should I give as parameter in the line Console.Write(hfd.Prod("Apple", 5)) ? (error: no overload method takes 2 arguments)
2) Console.Write(Prod("Apple", 5)); same error => is line Head hfd = new Head(); then unnecessary? Can i access method Prod directly from Main?
3) Apparently, the line Product obj= new Product(); is not necessary. Why?

Thanks

V

public class Product
    {
        public string Name { get; set; }
        public int Price { get; set; }
    }

    public class Head
    {
        static void Main(string[] args)
        {
           Head hfd = new Head();
            Console.Write(hfd.Prod("Apple", 5));
           // Console.Write(Prod("Apple", 5)); this gives the same error => no reference to class Head  needed?
        }

        public void Prod(Product p)
        {
            //Product obj= new Product(); why not necessary?
            if (p.Price > 0)
                Console.WriteLine("ok");
        }
    }