Thank you for your question.
My favorite part of your email, given that you are 12, is "I am amazing at pinpoint settings and receiving..." - Fantastic confidence that will serve you well later in the often cut throat world of collegiate athletics!
As you are 12 years old, I would not even consider specializing in any positions right now - Play every position you can, touch every ball you can, play on any surface and/or format that you can (indoor, sand, grass, doubles, quads, sixes, etc). This the time segment where your volleyball intellect and muscle memory is being formed.
Maybe you will be 5'7", but what if you have a great great uncle who was a 6'10" Norwegian and you jet up to 5'11? Don't limit yourself to the back row or the setting position as a 12 year old!
If you would "like to be able to attack.", then go attack - This is my point!
Now is the time to do it all, because soon you will be high school age and your club coaches will mandate that you play just one position because this is the nature of today's volleyball....specialization.
But, don't specialize until you have to specialize!