Speaking from experience-- learning to spin NICE yarn can take quite a bit of practice!
I learned to spin with purchased wool, while living in a place that was not suitable for keeping any kind of wool-bearing animal. So that's why I thought of buying it :)
I've also tried spinning cotton--...
With angora rabbits, you do not kill the rabbit to harvest the wool, so no worries there.
Shearing is one option, plucking or combing the wool is another option.
Wikipedia tells the basics:
https://en.wikipedia.org/wiki/Angora_rabbit
It depends on how big and thick you want the blanket to be...