Somebody Help me to fix this magneto issue

[ybo19091]

When i edit local.xml.sample to local.xml. and i have also created tmp folder on magento main folder but i am getting this issue. I am new. Somebody please help out.

My error:

There has been an error processing your request
Cannot send headers; headers already sent in /home/yagyaoli/public_html/aab/app/code/core/Mage/Core/functions.php, line 60

Trace:
#0 /home/yagyaoli/public_html/aab/lib/Zend/Controller/Response/Abstract.php(115): Zend_Controller_Response_Abstract->canSendHeaders(true)
#1 /home/yagyaoli/public_html/aab/app/code/core/Mage/Core/Model/App.php(1265): Zend_Controller_Response_Abstract->setHeader('Content-Type', 'text/html; char...')
#2 /home/yagyaoli/public_html/aab/app/code/core/Mage/Core/Controller/Varien/Front.php(80): Mage_Core_Model_App->getResponse()
#3 /home/yagyaoli/public_html/aab/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(202): Mage_Core_Controller_Varien_Front->getResponse()
#4 /home/yagyaoli/public_html/aab/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#5 /home/yagyaoli/public_html/aab/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#6 /home/yagyaoli/public_html/aab/app/Mage.php(683): Mage_Core_Model_App->run(Array)
#7 /home/yagyaoli/public_html/aab/index.php(83): Mage::run('', 'store')
#8 {main}