I am a newbie with Zen Cart, I just installed zen cart v1.3.8, havn't update and install any addon or module yet. I browsed around a bit and searched the forums, could not find answers for my questions (forgive me if I missed any). Appreciate if anybody can help.

1. I don't see anywhere I can process orders(charge and refund credit cards) after orders are received online. I don't have an account with any payment gateway yet, for instance authorize.net, etc. Will this ability show up once I have my account established with any payment gateway and reconfigure the zencart? or I just have to login payment gateway's system to charge and refund credit card? Why is this ability not available? Security concern? Regulation concern?

2. I don't see any link to either ups and usps to print shipping labels. Do I need to install additional modules?

3. I don't think I can modify orders, for instance, add items, modify quantity and price, etc. Only thing can be changed is the status. Am I able to do changes like I mentioned with a module?

Thanks ahead!