You have already been given some great advice. The best bow for me is not the best bow for you. Shoot a few of them and see what you like and what feels best to you.
Nothing wrong with buying a used bow, I shot used bows for the first 12 years of my bowhunting career and it worked great for me. I finally wanted one that fit me.
Go to a bow shop and get fitted so you know what you are looking for and making sure that you are using a bow that at least fits you. My first bow was 2" too long for my correct draw length. I could shoot it fine, but when I finally go to the right bow length, I had to learn to shoot properly.
I recommend finding a friend that is proficient or taking a lesson at an archery shop. It will help tremendously in the learning curve. While there is nothing highly technical about shooting a bow, there are steps that can be taken that make it much easier and eliminate some of the issues that beginners seem to run into.
Main points are grip and anchor point as far as shooting. Aim small, miss small is a mantra that you here and people ignore alot IMO. It is true. When you start shooting, there are drills that you can do to help narrow the shot on an animal. Shooting a target is much different.
Trying to decide what rest, arrows, tips, weight, etc can get overwhelming if you have never bowhunted before. Don't let it get to you, as you will change your mind multiple times for what you like.
I would start with a single pin sight and if you want, get an adjustable one. As a beginner, your shots probably won't be long but if you have an adjustable one, you can grow with it.
Good luck and enjoy!! Don't hesitate to ask any questions