We always go on holday early in the summer to Cornwall and love it. I don't like Newquay any more, it's really run down now and it's a bit of a shit hole these days
We always stay at a caravan park near St Austell called Pentewan Sands, it has it's own private beach and it's in a nice location to get to anywhere in Cornwall quite easily.
As said above Falmouth is really nice and so is boscastle, fowey, mevagissy, you can't really go wrong.