Yea, as others have alluded to, I suspect you have some catching up to do
Seems you've fallen for some of the many of the mis-perceptions circulating in common society. I'd say welcome and jump right in and get an education !
Polyamory - as the term implies - is about a LOT more than sexual activity, although that MAY be a part of it in the majority of cases (far from all).
Common error to many people.
Keep reading & learning. It will start to click in. Then it will make more sense.