So is Python even needed for modding or is it just a waste of time to learn if you want to mod and create things in Warband ?
The post above yours puts it quite well: You will very rarely, if ever, need it. If so, it is only to make something easier that you can also do in a more tedious way without Python.
As for myself, I don't think I've ever touched Python to do things with Warband - I wouldn't say I know the language, and I've never felt the need to use it for Warband. The only thing that can be helpful is having a grasp on the syntax, but you will usually get that fairly quickly through trial and error anyways.
If you wanna get started, I'd say check out some of the guides around the forums and what Earendil linked above, and from that point just do what you want to do - find something that does something close to it, copy it, change it to what you need. With a bit of time, you will be able to create things completly on your own. And if you ever run into something that you need Python for, pick it up then.