For a rifle, anything above 243 in caliber will be fine for deer and all of them will kill with the same intensity. However you must find one that fits you and feels good. Then you must spend time at the range becoming comfortable and familiar with the weapon.
for advice on deer....WOW what a question

Spend time in the woods now and as often as possible prior to the opener. Start by looking for trails around edges (where 2 types of terrain come together) and at low spots in creeks. Sooner or later you will start seeing small patterns where deer have been and where they seem to spend more time. After you find their trails, start looking for food sources. This can be as large or as simple of a task as you want it to be. Acorn trees of all types will feed deer when dropping. All types of agriculture will draw deer. All types of browse will draw deer. Walk the trails you find and see what is on or near them as far as food. Then start looking for ways for you to set up downwind of those areas.
Keep up these basic patterns and you will start finding deer. After you learn the woodmanship skills, you will begin to refine your tactics.
Go though this and other forums for already printed advice. There is a lot help already waiting for you.
Welcome to the world of the hunter! Glad to have you. Please be ethical and safe.
Jim
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