Empty a linked-list object

I have my linked list code:

#include <string>
#include <iostream>
using namespace std;

class Node
{
public:
    string name;
    int age;
    Node *next;
    Node(string name, int age)
    {
        this->name = name;
        this->age = age;
        this->next = nullptr;
    }
};

class List
{
private:
    Node *head;
    int size;

public:
    List()
    {
        this->head = nullptr;
        this->size = 0;
    }

    void insert(string name, int age)
    {
        Node *nodenew = new Node(name, age);
        nodenew->next = nullptr;
        if (this->head == nullptr)
        {
            this->head = nodenew;
        }
        else
        {
            Node *auxi = this->head;
            while (auxi->next != nullptr)
            {
                auxi = auxi->next;
            }
            auxi->next = nodenew;
        }
        this->size = this->size + 1;
    }

    void print()
    {
        if (this->head == nullptr)
        {
            cout << "List is empty"<<endl;
        }

        Node *auxi = this->head;
        cout<<to_string(this->size)+" users in the linked list"<<endl;

        while (auxi != nullptr)
        {

            cout << auxi->name << ", " << auxi->age << endl;
            auxi = auxi->next;
        }
    }
};

int main()
{
    List linkedList;
    
    linkedList.insert("David", 56);
    linkedList.insert("Susan", 25);
    linkedList.insert("Kim", 41);
    linkedList.insert("Charles", 23);
    linkedList.insert("Bob", 20);
    linkedList.insert("James", 75);
    linkedList.insert("Carl", 36);
    linkedList.insert("Andy", 78);
    linkedList.print();
    return 0;
}

As you can see I did insert method, print method. And now want I want is to delete all nodes in the linkedList object, so I would like to know if there is some way to make for example something like linkedList = nullptr or something similar to delete all data in my linked list.

I tried to make that in the main method:

linkedList = nullptr;

But my compiler shows me this error:

no operator "=" matches these operands

I hope you can help me, thanks.