Error messages~

[Pear]

Hello! c: It's me again.. Recently my host moved some sites over to a different server (or something like that..) and so my site was one of the ones that moved. However, now I am getting a ton of error messages. I am not experienced in coding at all, so this is all foreign language to me. Does anyone know how I could fix it? c: Thanks for any help<3
This is on the page to use an item:
"Strict Standards: Declaration of DropdownList::add() should be compatible with GUIContainer::add(GUIComponent $component, $index = -1) in /home/capifore/public_html/classes/class_dropdownlist.php on line 184"


And these also show up on the ACP:
"Strict Standards: Declaration of AdminSidebar::setDivision() should be compatible with Sidebar::setDivision(GUIComponent $module) in /home/capifore/public_html/classes/class_adminsidebar.php on line 18

Warning: Cannot modify header information - headers already sent by (output started at /home/capifore/public_html/classes/class_adminsidebar.php:18) in /home/capifore/public_html/classes/class_cookies.php on line 109

Warning: Cannot modify header information - headers already sent by (output started at /home/capifore/public_html/classes/class_adminsidebar.php:18) in /home/capifore/public_html/classes/class_cookies.php on line 111

Warning: Cannot modify header information - headers already sent by (output started at /home/capifore/public_html/classes/class_adminsidebar.php:18) in /home/capifore/public_html/classes/class_view.php on line 257"