Very basic singly linked list Here is implementation for singly linkedlist. Any suggestions are most welcome

package linkedlist;

import java.util.Scanner;

public class linkedlist {
    private int size=0;
    private Node newNode,oldNode,firstNode,displayNode;

    public void createNode(String value) {
        if(size==0) {
            newNode=new Node(value,null);
            firstNode=newNode;
            size++;
        }
        else {
            oldNode=newNode;
            newNode=new Node(value,null);
            oldNode.setNextNode(newNode);
            size++;

        }

    }

    public void DisplayLinklist() {
        displayNode=firstNode;
        while(true) {
            System.out.println(displayNode.getItem());
            displayNode=displayNode.next;
            if(displayNode.next==null) {
                System.out.println(displayNode.getItem());
                break;
            }

        }
    }


    private class Node{
        private String item;
        private Node next;

        Node(String item,Node next){
            this.item=item;
            this.next=next;
        }

        public String getItem() {
            return this.item;
        }

        public void setNextNode(Node address) {
            this.next=address;
        }
    }

    public static void main(String[] args) {
        linkedlist mylinklist=new linkedlist();
        Scanner in=new Scanner(System.in);
        System.out.println("Enter the string value you want to save or press 'n'");
        String input=in.next();
        while(!input.equalsIgnoreCase("n")) {
            mylinklist.createNode(input);
            System.out.println("Enter the string value you want to save or press 'n'");
            input=in.next();
        }

        mylinklist.DisplayLinklist();

    }

}


This is very basic version and first time I  am doing Linkedlist. I am not using any iteration, but just wanted to confirm am I on the right path?
size++ should be extracted from both branches and called only once
there is no need to cache instance variables where local method variables should be used instead: newNode,oldNode,displayNode
prefer while(currentNode != null) over while(true) and currentNode should start with firstNode and be chained inside the while-loop as currentNode = currentNode.next
you should also provide remove and iterator functionality
DisplayLinklist should not be inside this class and it should be camel cased
variable firstNode is usually called head
class linkedlist should be called LinkedList
get rid of unwanted blank lines