Hi Michelle Shumate, I can see that your phone model is out of date, there is one small problem, and that is that the only CM ROM available for your device, that I've known so far, is still GB, and checking the CM webpage notice that the ROM has been discontinued. But if you still want to go ahead and do it, I'll post some links and video to help you out. Notice that this is on your own and I won't be responsible if anything goes wrong or your brick your phone.
The first thing you need t do is root your phone. Here is a YT video on how to root with one click and also how to install a custom ROM.
How To Root And Install Custom Rom For Samsung Indulge
Before proceeding with the root, make sure you have the usb drivers for your model install in your computer.