If you go slightly north of newquay there is watergate bay which all forms of kiting are permitted on and there's a kite shop / school right there on
the beach.
Also nearby is Skyhooked (Dom's) kite park which has a number of ramps / lumps to use.
Of course the ultimate location i believe is Gwithian -
http://www.bbc.co.uk/cornwall/surfing/north_gwithian.shtml
HUUUUGE beach, many kiters use it, as it's so big it's never really a problem getting in other peoples way.