Предлагаю создать группу для изучения Java SE

import java.util.*;
 
public class Person{
    private String firstName, lastName;
    private Date birthday;
    private String address;
    private String phoneNumber;
    
    public Person(){
        this("Somebody", "Somebody");
    }
    
    public Person(String firstName, String lastName){
        this.firstName = firstName;
        this.lastName = lastName;
    }
    
    public Person(String firstName, String lastName, Date birthday, String address, String phoneNumber){
        this(firstName, lastName);
        this.birthday = birthday;
        this.address = address;
        this.phoneNumber = phoneNumber;
    }
    
    public void setFirstName(String firstName){
        this.firstName = firstName;
    }
    
    public String getFirstName(){
        return firstName;
    }
    
    public void setLastName(String lastName){
        this.lastName = lastName;
    }
 
    public String getLastName(){
        return lastName;
    }
    
    public void setBirthday(Date birthday){
        this.birthday = birthday;
    }
 
    public Date getBirthday(){
        return birthday;
    }
    
    public void setAddress(String address){
        this.address = address;
    }
 
    public String getAddress(){
        return address;
    }
    
    public void setPhoneNumber(String phoneNumber){
        this.phoneNumber = phoneNumber;
    }
 
    public String getPhoneNumber(){
        return phoneNumber;
    }
}