Hi Ron,
Welcome to Train Tech!.
we have a pinned topic at the top of the forum called My the train tech index. It contains a lot of useful information regarding all aspects of lego trains and actually has a section with information for beginners. We have had a few people ask questions like this and before and its been extensively covered by others. I would start be reading those topics to get some ideas as to what may be the best option for you as each train system has its advantages / disadvantages against the other. Its unlikely that 9v will be re introduced so any track that you buy will most likely have to be from the likes of ebay or brick link.
Personally I think if your just starting it may be worthwhile getting the new passenger train. It gives you some basic track and every thing you need to motorise it and control it or gives you the basic parts to create your own three car train. Depending on your country this will most likely be the most cost effective way to start out too.
I am sure some of our more active members will be along to add comments to cover any things I have missed but I would defiantly advise checking the train tech index.