I hula hoop about 30 minutes a day. I use a "weighted" hula hoop. Although, you should be more specific when using the term "weighted". Are we talking water, sand, or just a heavy pvc? Also, the size plays a huge factor. Try it out. If it hurts, then go with a lighter hoop. Or buy padding for the hoop. Or try a larger diameter hoop. If it is heavy, but thin, it will hurt more than if it is heavy, but thick. The thicker the hoop is the better. 1" is about where I reccommend begginners aim for. Also, be aware that if you haven't hooped in many years, there is strain on places you may not expect. Your knees, for instance, are likely to feel the strain. Start out slow. Go for a large hoop (at least to your belly button when standing up, though bottom of your rib cage is better) at a thick diameter. Aim for 3-5 minutes of hooping a day, and slowly increase. If you feel discomfort, stop. If you start to bruise, stop. Try to go with 100-120 psi tubing, any higher will be too stiff and might bruise your hips.
Mostly, just play with it. You need to get your body back to a point where you are used to doing this activity. If you haven't run in 20 years, then try to go out and run a marathon with no training you are going to get yourself hurt. You have to work your way into things. Start out small, and work your way up.