Signon Problems

Help! My web host is Blue Host. I keep getting warning messages after I login. After installation, I added this theme: beautiful-sunrise-10; then after I make a single change I get this Warning:

Warning: Cannot modify header information – headers already sent by (output started at /home/basebal9/public_html/wp-content/themes/beautiful-sunrise-10/functions.php:72) in /home/basebal9/public_html/wp-login.php on line 12

Warning: Cannot modify header information – headers already sent by (output started at /home/basebal9/public_html/wp-content/themes/beautiful-sunrise-10/functions.php:72) in /home/basebal9/public_html/wp-includes/pluggable.php on line 331

How do I fix this? Does this happen with all themes or am I doing something wrong? Please help! WordPress support is not open until Monday from 9-5!