Penzance in the best place to launch with good secure parking not far from the slip. Isles of Scilly Parking Co.
My favourite camping is on Bryher with excelent moorings very close with Bryher Boatyard, Isles of Scilly
You can take boats over on the scilonian ferry with all your camping kit.
But everythingneeds to be booked well ahead as July is peak season.
Navigation, do a thorough passage plan, so you know where you are going, there are lots of rocks, sand banks and big tides to catch the unwary.
Remember plenty of fuel, as if you have a big head sea you will use 2 -3 times your standard fuel consumtion.
Some of the best boating and beaches to be had anywhere!