unable to access admin panel of my wordpress site

Hi

I am unable to access admin panel of my wordpress website. URL is https://www.contentmarket.com.

Admin panel is not appearing when i click on https://www.contentmarket.com/wp-admin, the error is
Warning: Cannot modify header information – headers already sent by (output started at /home1/contentm/public_html/wp-content/themes/corpbiz/functions/woo/woocommerce.php:2) in /home1/contentm/public_html/wp-includes/pluggable.php on line 1178.

Kindly resolve the issue asap