I am developing some code to send data via the I/O port and the USB port. What are the port numbers for both of those ports? Thank you in advance.

I'm going to assume you're talking about the TI-84+(SE) since your signature contains information about that, and the only other calculators that I know of that has that combination would be the CSE and the Ti-89T

Look at the link below for comprehensive information.
http://wikiti.brandonw.net/index.php?title=Category:83Plus:Ports:By_Address

The I/O is directly controlled by port 0. It's mostly a simple on/off for each of the two lines.

Ports 08,09, and 0A are I/O link-assist ports if you want to use TI's low level protocol for sending and receiving data.

Most of the ports past 4A (4A,4C,4D, 54-5B, 80,82-9A) involve USB in some manner, and you'll need to mess with a number of them to directly drive the USB protocol yourself. Look here for more information. It's a bit much, and most people simply use a series of romcalls to set up and possibly do all the fancy USB work for you. Actually writing your own driver tho? Good luck. You'll seriously need it.

This page has a ton of information on USB: http://wikiti.brandonw.net/index.php?title=83Plus:OS:84_Plus_USB_Information

As Iambian said, writing code to control USB isn't easy.

So, these ports would directly apply to the GetCalc( command, correct?

The only possible relevancy that question has is if you intend on disassembling the responsible routine, since the answer to that question has precisely zero bearing on any possible thing you could ever do with the ports.

If you are, the answer is a sorta "yes". What you'll end up finding is couple 16KB chunks of OS code, about 90% of which is relevant to USB hardware and the rest of it is just there to mess with your head.

Seriously, though. If you want to actually do what you say you intend to, you need to put much more substance in your posts. If you can't, you should ask your questions in the IRC channel #cemetech , which is also accessible via the SAX widget (found on the left side of any cemetech.net webpage if you'll scroll down a bit). Once you've done that, gather up what you want to ask and post that.

tl;dr: Oneliner posts are frowned upon. More substance, pls.