A simple shopping cart you can build by cutting and pasting from one of the gadzillion examples all over the net. The newbie section (where we are, right now) is a good place to discuss and ask questions about methods used and discuss various options.
Properly securing your site is a whole other ball game which is entirely more complex and is discussed and rehashed here all over the place. It pops up in the newbie section frequently, but often exceeds the scope of this area and people just learning PHP.
The complexities involved choosing the right E-Commerce solution is a whole new area of discussion that exceeds the previous issues on so many levels to make it hard to see the relationship. It is kind of like discovering how easy it is to ride a tricycle, so you decide you are ready to pilot a submarine. The first step is to learn the difference ... the next is to keep the cart on the dirty end of the mule.
