Hello, before answer your question:
1. Is it you plan to receive your customer money from paypal?
2. Or credit card payment?
For paypal,
You can register a merchant in Paypal. Paypal will give you a merchant code and you just need to paste it into your hosting. It has a form ready over there.
If you plan to create a Ecommerce site, I suggest you use either one:
opensource & commercial softwares:-
MyMall, Drupal / UberCart, OSCommerce, VirtueMart, Joomlah, ZenCart, CubeCart, WebShaper, WHMCS, Magento, ECShop, PrestaShop.
For credit card merchant, try:
http://www.netbuilder.com.my/html/modules/tinycontent/index.php?id=49
Hope this help