If you go to the iPad 'Home' screen you'll see the 'Contacts' app there. Open the app and you'll see a list of your contacts. They're listed alphabetically and you can jump to a specific letter of the alphabet by touching that letter.
So, if you had a contact 'Mum', then you could touch the 'M' letter on the left hand side of the screen and the Contacts app will jump to display all your contacts starting with the letter 'M'. Of course, 'Mum' might not be the only contact you have starting with an 'M', so you'll need to look for 'Mum' in the list on the left hand page of the Contacts book (you might need to scroll up and down if you've lots of Contacts). Once you find 'Mum', touch the name and the details will appear on the right hand page of the Contacts book. Now touch the 'Edit' button that appears at the bottom of the right hand page. Make the changes you want and then press 'Done' (top right hand side of the page) or 'Cancel' (top left hand side of the page).
You can create new Contacts using the '+' sign that's at the bottom of the left-hand page. Contacts can display 'Groups' of contacts that might have been imported/sync'd from a PC or Mac but it cannot create them. If you need to create a Group there are a number of third-party apps that can do this - in my opinion the best is MailShot.
Tim
Scotland