Being completely new I'd also recommend using a Pro Shop for your purchase. I would stay away from EBay or other such places. You probably don't have the knowledge to pick a bow with the correct draw length and this is crucial. Using a good shop will benefit you in that you'll get measured close enough for the right draw length and then pick a bow that is adjustable up or down at least an inch from said measurement. Be careful not to overbow yourself, meaning draw weight. Depending on what you intend to hunt there is no reason to choose a 70# if you cannot handle it -----easily. Getting the correct arrows and other eqquipment is paramount, too, and this is where a competent shop comes in handy.
There is nothing wrong with used. As mentioned, a lot of people buy a new bow every year just for bragging rights or because they desire to. There are tons of good used bows to be had.
If you find a good shop they should allow you to shoot any bow you think might fit your needs. This is another reason for a shop. Look at many. Shoot as many as you can and don't rush it. Keep notes on how each felt and performed and make an informed decision based on your notes. You'll end up a much better shooter for it.