Have you taken a look at Utahjazz's tutorial? It's honestly a great one if you're just starting from scratch. I didn't know anything about animation or 3d models before i started making units and it explained it perfectly. I believe most programs he used are quite old, and you can find a free version of most of them online at this point. Im not entirely sure about Poser, but I've heard Daz studio is quite similar.