Well, first of all, Welcome to The Forums!
...And if you have versions 1.17 to 1.20.0003, then your able to use Dark Ai, which allows you to have basic enemy and ally scripts to add to your characters. They work pretty well for the most part, but if your looking for custom Ai, then I'm sure the rest of the forums will help since I don't know where to begin with Dark Ai.
Those version also give you the feature of ragdoll, you can also find a few scripts laying around here.
Version 1.20.0003 can be found here:
http://forum.thegamecreators.com/?m=forum_view&t=197293&b=21
Other versions here:
http://www.thegamecreators.com/?m=view_product&id=2001&page=Files
Don't worry all updates are free!
If you have further questions, feel free to ask.
Oh, and don't start with a large project when your just starting out, play around a bit until you have good knowledge on the software and scripting language. On the download page above, you'll also find an FPI edit pad, it's free and easy to use, plus there are great tutorials on scripting here! Thats how I learned!
Fulfilling the Nerevarine Prophecy, one trial at a time, because I... Am... The Nerevar!