title: Add a custom page with form in wordpress using plugin for frontend user
body: <p>hi I am very new to wordpress plugin development, I created a plugin that is adding a Sidemenu to show jquery dialog,</p>
  
  <p>Now I'm trying to show a form in a page to front-end users, but i'm very confused how to start,</p>
  
  <p>I want to show a link in side menu for front-end user, when user click on it i want to open my custom page with plug-in.
  (Url should be like this after clicking: demo.com/my_page.php).
  I googled it but not found anything understanding some are suggesting templates(I don't know about them yet).</p>
  
  <p>Will you please suggest me the best way to do this.</p>