After long time search on google, I have finally succeeded to get the ID of Page in Wordpress. To find it is easy, if you are expert in wordpress, otherwise, you can spend whole day. So, today, I am writing its steps.
1st Step : Login your wordpress account.
2nd Step : Go to All pages
3rd Step : Search the page whose page id, you want to find.
4th Step : Carry your mouse on its edit button and see below the status bar, you will see its page id. following is its screenshot.