How to Change Default Pages text?

[gloryKAT]

I can't find where/which file to edit to change default text (if it's possible). For example, if I wanted to change the text that says "The Trade Station" to something else, how would I do that?

Another question, I am trying to fix this error for members on my site:

'Fatal error: Uncaught exception 'Exception' with message 'Cannot recognize usergroup category for this user, he/she may be a guest, a bot, or else...' in /home/magicval/public_html/classes/class_membercreator.php:28 Stack trace: #0 /home/magicval/public_html/classes/class_membercreator.php(32): MemberCreator->getgroupcategory() #1 /home/magicval/public_html/classes/class_mysidia.php(270): MemberCreator->create() #2 /home/magicval/public_html/classes/class_mysidia.php(165): Mysidia->getCurrentUser() #3 /home/magicval/public_html/classes/class_initializer.php(106): Mysidia->__construct() #4 /home/magicval/public_html/classes/class_initializer.php(42): Initializer->initialize() #5 /home/magicval/public_html/index.php(81): Initializer->__construct() #6 /home/magicval/public_html/index.php(90): IndexController::main() #7 {main} thrown in /home/magicval/public_html/classes/class_membercreator.php on line 28'