4.0 back t0 3.9.2!

I recently upgraded to 4.0 which i was left with a blank screen so have thereroe decided to return back to 3.9.2 upon installing i went to my website and the website is back up with this long string of text above:

Notice: wp_enqueue_script was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. Please see Debugging in WordPress for more information. (This message was added in version 3.3.) in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-includes/functions.php on line 3245 Notice: wp_enqueue_style was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. Please see Debugging in WordPress for more information. (This message was added in version 3.3.) in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-includes/functions.php on line 3245 Deprecated: Assigning the return value of new by reference is deprecated in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-content/plugins/woosocialbuttons/woosocialbuttons.php on line 399 Notice: Undefined property: WP_Query::$post in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-includes/query.php on line 3700 Notice: Trying to get property of non-object in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-includes/query.php on line 4095 Notice: Trying to get property of non-object in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-includes/query.php on line 4097 Notice: Trying to get property of non-object in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-includes/query.php on line 4099 Warning: file_put_contents(/var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-content/plugins/premium-seo-pack/fb_locale.xml): failed to open stream: Permission denied in /var/www/vhosts/fibreglass-supplies-uk.co.uk/httpdocs/wp-content/plugins/premium-seo-pack/modules/title_meta_format/init.social.php on line 439

can anyone help please? thank you