allegro PAD & footprint

hi I used altium 3 year but now I need to design high frequency and impedance matching and DDR3 and etc so I changed my plane and I want to use allegro Cadence but I have many problem and I don't have good tutorial that start from orcad CIS shematic and end it in allegro PCB.
in altium designer we don't have PAD! I am confused!! I understood if I want to create new footprint I should attach it to pad that I created before.
but I found many footprint in the internet, with themselves PAD. is it need to attach my new PAD to them? how I can do? if it doesn't need why I should create PAD?
excuse me for my little knowledge in Cadence alllegro and also my bad English.
any help would be greatly appreciated.

Sincerely yours,
Siyavash.

Hi siyavash,
please find the following link it may be help.
www.parallelsystem.uk
and check this link also
https://www.edaboard.com/threads/206372/
http://www.referencedesigner.com

Hi kapil,
thank you for your good reply,
I saw these file before but my problem doesn't solve.
I will be glad if you tell me in this topic, I am really confused,
best regards,
Siyavash.

This one is the best tutorial to get started on Allegro

http://www.referencedesigner.com/tutorials/allegro/allegro_page_1.php