I suggest you go to ebay and look at bikes. You don't have to buy one. But it will give you an immense variety of bikes to look at. And all of the different things that go with them. That's one way to learn.

And my opinion on Walmart bikes and the higher end bike that you're looking at, is that the Felt will have better components that will be easier to adjust, will be more durable, and are of higher quality than the stuff they use for those bikes.