I'll wait for actual staff people to answer some of your questions, but we just had an event this weekend so they'll probably need a little time to wrap up logistical stuff and recover.
Breakfast, lunch, and dinner on Saturday are all provided with the meal fee. There is at least one fire pit on site (probably more, but one I can think of right away) and as far as I know, campfires are allowed as long as they're well-tended. I don't see why there would be any issue with the cooking fire, but I don't really have the authority to speak on that.
Camp Pokanoka is a camp site with a handful of buildings that we have access to. The event runs from Friday night through Sunday morning, so unless you can't make the whole event (which is fine, if that's the case) almost everybody sleeps on-site. There is enough sleeping space for everyone, so you won't need to find a hotel or anything, but it can get slightly cramped. The main tavern building has camp mattresses (the type you see at most boy scout/girl scout camps, if you're familiar with those) on the floor. There are also small primitive cabins with bunk beds, but they're not really insulated at all so you'll want to plan ahead on warmth if you intend to stay out there - it's not gonna be much warmer than tent camping in the same conditions.
Whether you want to PC or NPC your first game is a personal decision. A lot of people advocate for NPCing the first game, as it gives you a chance to learn the combat system and other rules, but if it's your first time larping there really isn't a replacement for PCing right away and just stumbling head-first into the unknown. There are benefits to either direction. For me, it'd largely come down to whether or not you have costuming, weapons, props, etc ready for a character.
If you want to NPC, you should bring basic bedding (blanket & pillows), dark base layer clothes for a couple days (costuming and weapons will be provided), plenty of extra socks and maybe a back-up pair of boots (for sweaty feet and/or cold, wet weather conditions), maybe some snacks, and general cold weather clothes like gloves and a hat. Dress in layers. Most things are provided for NPCs.
If you want to PC, you'll want to bring all of the same things, but instead of just plain dark base clothes, you'll need character costuming (doesn't have to be amazing your first time out), any makeup or prosthetics you need if you want to play a non-Human race (though you can usually borrow from another PC if you don't have everything right away), whatever weapons and armor you want (again, you can probably borrow some your first time out), and either lots of pockets or a couple nice belt pouches to carry things with you. I'm not going to say you should dress in jeans and a winter coat, but safety and warmth should take priority over costuming at a winter event. Just avoid obvious anachronisms like blue jeans, white tennis shoes, or brand logos on your stuff. Feel free to wear warm layers under your costuming if the top layer isn't particularly warm on its own.
I will have my makeup kit at the next game (including a couple pairs of elf ears and a pair of horns if you let me know in advance) and I don't mind lending stuff out. If nobody else has weapons they can lend you, I might have what you're looking for, but I'll let the more local players volunteer those first.