date picker help please...

The default Gravity Forms styles aren't being loaded on your page.. that's why the datepicker isn't displaying properly.

If you're using the shortcode to embed the form in a page, then you should check to make sure that your theme is including the wp_head() function in the header.php file and the wp_footer() function in the footer.php file. These are required to load the appropriate style sheets and scripts that the plugin uses.

You can find more information on those functions here..

http://codex.wordpress.org/Theme_Development

If you're using the function call to embed the form directly into a page template, then you'll need to manually enqueue the scripts by placing some script into your functions.php file.

You can find the information on embedding the form and enqueuing the scripts on the documentation page here.

http://www.gravityhelp.com/documentation/embedding-a-form/

Once you've got the style sheets loading properly, your display issues should be resolved.