I can post as both an Adoption Coordinator for a parrot rescue and having adopted a macaw... actually he adopted me...
I would suggest finding a rescue near you and volunteering for a short time, you gain valuable hands on experience and knowledge, along with the reality of macaw behaviors and start to learn a bit about body language...
With a macaw, let the bird pick you, if you let the bird choose literally the bond is almost immediate. From the moment Max stepped up on my arm, it was clear to everyone in the room that I had a macaw whether I wanted one or not. And more then 3 years later, he is still my big baby boy... He was 25 when he arrived at AHW, so very much past his sexual maturity and an adult.
I've posted videos and pics in the past of Max and I together, but he is a great example of letting the bird choose! A good rescue / shelter will want you to come for multiple visits and get some hands on experience - what I joked was Macaw 101 training

Even as the Adoption Coordinator for the shelter, I had never had a macaw, nor was interested in one, and I went thru the hands on 'Macaw 101' visits too... and it was invaluable for preparing me to bring home a big guy. Between body language, nutrition specific to macaws, and how to deal with a hormonal monster with a can opener on his face - truly those visits are beyond measure valuable!
This is Max the other week after I got home from a community education expo day...
[ame="https://www.youtube.com/watch?v=S_B90f809jQ"]Max - YouTube[/ame]