I have found that when I sail with my father with a total of about 360 lbs, we need about 20mph winds or a little less to be able to fly a hull. Also, since your are still getting used to the boat, some advice I could give would be not to be scared off by the strong puffs. When I let my crew skipper on 15+ days, he always has the tendency to immediately spill the main while in a puff and that is another reason why you might not be able to get a hull up. When the wind picks up, dont be afraid to just keep the main cleated off and let the boat take off. It took me a while to get used to leaving the main cleated and just letting the hull rise in the puff then come back down at the end of it, but once you get used to it, your sailing trips will be so much more fun.

My $0.02