I haven't had the chance to bow hunt yet but I am slightly further along the curve than you are but there are a few things that helped me and maybe they will help you too? The first time I shot a bow, I shot a family members 80lb draw compound and being lightly built man that I am, it taught me the hard way, very quickly that heavier is bad. Do not go too heavy, resist the urge at all costs. A 60lb bow is more than enough for most plains game and even that will likely be too heavy, and although the idea of being able to shoot a buff is great, you're probably not going to get the chance with your first bow.
Like was mentioned above, get your bow set up properly by someone who has a good reputation in the field. Corrent draw length is key.
Get someone who knows what they are doing to teach you the basics of shooting form, preferably over a few days or weeks so they can keep bad habits in check - it will make the difference between shooting 10 shot groups the size of an orange at 20m on your first day and losing all hope and confidence because you're making an elementary error that you don't know you are making.
Practice practice and more practice is key. Don't just stand there and shoot until you can't draw the bow anymore as your form and confidence will start to suffer long before this stage. Focus on form for each shot and focus on consistency between shots. Don't shoot too much on any given day, remember a fresh body and mind will always shoot better and learn faster than a tired frustrated one that has been firing all afternoon without a break.
Good luck!!
