For 8 months of the year we get good winds down here in the Florida Keys, (Oct-thru-May) and it is normaly warmer than anywhere else in th U.S.,so come on down.
I'd second the vote on Florida, but there are great spots all over. If you are coming in the summer, get to the west coast of Michigan, fresh water riding with great beaches.
go san padre island , texas as there's two sides of waves and flat waters so u could learn at flat water , easy than waves and later after improvement with your kiting ability , u could ride on waves
anyway there's few beach locals require iko insurance before u can kiting at south fla and other locas dont require iko insurance cause too many accidents at south fla lead to order iko insurance on kiters get permitt access there