I've got a couple of friends that just got hoops that haven't been able to figure it out yet either. I tell them that it's like waterskiing or riding a bicycle. At first you try too hard and can't do it, but then suddenly you get it and it feels so natural. I did spend plenty of time moving my hips in an exaggerated fashion and picking the hoop up off the ground. I was also totally out of breath after a minute or so. Now I can hoop for half an hour or more and barely break a sweat. So all I can say is, keep trying - you will get it.
I would love to learn how to do tricks, like hoop up and down my body and over my arms, but I think that I will need a different kind of hoop for that.
I do wear some light wrist weights now while I hoop, I don't do anything fancy with my arms, I'm too uncoordinated, but since my arms are kind up raised up I feel that it helps.