Well, you could just let the mod of the thread handle the 'how long does it take IC part'. The cool thing about the game is that while you're getting training in one thread, you can just start another that takes place before or after that, so you don't have to wait for your training to finish before doing something else (
more info on timestamping). But to answer your question, the training thread itself normally takes a cycle or maybe two or so, but you need to gather some experience along the road before you can move to the next level as well (
info here).
Only a few tribes don't bother with visas (I know there are some giant and katta tribes). The only difference as a barbari is that you will be stopped at city gates when you try to enter and that you can be legally enslaved. I'm not entirely sure what happens next when you walk up to a gate, but I think you'll either end up in jail or at the aediles office to get you your own visa (depending on your actions). Less money is up to you to decide and so is having a home. But normally you'll probably have no money and a home somewhere in the wilderness (unless you are wandering or something), but I figure it won't have monetary value.