I know you'll get a lot more expert answers than this, but this will start you off anyway.
Widemouth Bay, Bude, North Cornwall isn't the best surf spot in Cornwall, but I'd say it's not bad. It should definitely be OK for beginners, but for intermediate it would be pretty weather dependent (check Zuma Jay surf cam http://www.zumajay.co.uk/surf-check-wid ... de-webcam/
One of the real plus points of Widemouth is that you get to park the car right on the beach just about, which is a real help when you want to unload, or just see your car from the water. It's a council run carpark, so costs a few quid. In season (Easter to late Sep) there are life guards, and you can leave the car keys with them (or under the hub cap....) - but the lifeguards go off duty at 6pm so you'd have to collect by then (or be stranded...).
There's also quite a lot of holiday cottage accomodation just behind the beach, so you could be based there and just walk in and off the water daily. Quite a few casual eateries (and one v. nice one called Elements on the cliff top - for the last day blow out!). There's some camping too nearby, and one of those holiday chalet villages further along, but would be a bit of a trek with boards and no car. Or you could stay in Bude itself (need transport, it's a couple of miles north). Bude has two other surfing beaches, Summerleaze/Middle Beach and Crooklets, which are generally less good than Widemouth, but depends on daily conditions. Warning - Sumerleaze failed the clean water test by the Marine Conservation Society!
Widemouth has a good few surf schools that mostly cater to local schools and tourists, supply wet suits (you'll need summer wet suits in Cornwall!)(possibly shorties OK as water warms) (but the upside is no sharks....
)and boards. There are some on the spot board hire places too, no idea of the quality of the boards or the range. Better to hire from Zuma Jay in Bude but you would need transport then.
I don't know how much localism there is, but in the main school hols season (End July through end August in the UK) the beach is pretty much family full, with surfers kept to a separate areas (two on Widemouth) and policed by lifeguards on jetskis. Body boarders in the swim-only areas. It can get croweded. I would surmise that most locals (and non-beginners) will take to the water early and late to avoid the holidaymakers.
If you have transport, then of course you can drive north and south to other surf spots. Newquay is probably about an hour and a half's drive away, Croyde ditto in the other direction.
PS - lots of your fellow compatriots in Cornwalll