This WP_Spamshield Contact Form is in the WP Editor already. When you are writing your new page, you will find it in the text editor toolbar in a box labeled "WPSS Contact Form". I have to insert here that this option is only in the Pages editor. It's not available in Posts.

After you have written your article, you need to decide where you want the contact form to be inserted. Then go to the text editor, place your cursor in the appropriate spot and go to the WPSS Contact Form icon in the toolbar and just click on it.

The code will appear in the spot you have chosen. Back in the visual editor, the code will appear where you want it. Then when you preview the page, the form will show right where you put the code.