Changing Text

Hi, I am a WP Virgin…have left the darkside of Joomla and now trying with WP, one thing I am stuck on is changing the text in certain areas
ie, I am in the UK so we dont use States Zip Code etc etc I would like to change these to Regions, Counties etc, in joomla you just go into the ini files and change them from there but struggling with WP, any pointers greatly appreciated, and can I add the employeepress is the best and by far most thought out job board package out there

Thank you for a great package