I'm gonna give you some pointers, but you need to try to do this as it's very basic and it's always good to practice.
A basic find in cake is in the form of
$this->ModelName->find('all');
This in its default form does a SELECT * from model_names (convention is to have singular ModelName for plural table name - model_names)
To add conditions:
$this->ModelName->find('all', array('conditions' => array('ModelName.x' => 1));
To add AND conditions
$this->ModelName->find('all', array('conditions' => array( 'ModelName.x' => 1, 'ModelName.y' => 2 ));
To add OR conditions
$this->ModelName->find('all', array('conditions' => array( 'OR' => array( 'ModelName.x' => 1, 'ModelName.y' => 2 ) ));
To combine both
$this->ModelName->find('all', array('conditions' => array( 'ModelName.y is not' => null, 'OR' => array( 'ModelName.x' => 1, 'ModelName.y' => 2 ) )); // where y is not null and (x = 1 or y = 2)
http://book.cakephp.org/1.3/view/1030/Complex-Find-Conditions
(btw I'm sure there will be users giving you the exact answers, so just take my answer for your reference :) )