Welcome to Bloodstock!
Much of what you've asked can be found here:
https://www.bloodstock.uk.com/pages/event-info (Top menu -> Info -> Event Info)
The car park is roughly 5 to 10 minutes away on foot. There's a manned temporary pedestrian crossing too so there's going to be a bit of standing around. The first part of the walk can be a bit uneven so watch your step.
https://www.bloodstock.uk.com/downloads ... te_Map.jpg is this year's site map for some rough reference points
If you're on facebook you might like to search up the (unofficial) Bloodstock Loners and Newbies page, where you would find a bunch of welcoming folk and a great General Advice post from one of their admins. If you're looking for a place to camp for some guaranteed friendly atmosphere between arena visits, you can look for worse places.
If you want to camp on your own, Midgard is the traditional "party site" at night so if sleep is important to you, try looking further afield - generally speaking the further away from the arena the less likely you are to be kept awake by bin jousters.
To address your tent size concern, a 4 man tent isn't going to draw the ire of anyone. If you rocked up with an 8 man castle you might get a few dirty glances from fellow campers but even then you're unlikely to find busybody security arriving with arms folded.
Toilets are usually pretty good here. Just bring a couple of bog rolls each in ziplocked bags (because rain affected bog roll is suboptimal arse cleaning material). If you're in the arena, just take some sheets in case you're caught short as well as some hand gel. Arena bogs are heavily used and paper isn't always there. Urinals are fixed to the fences at the end of the blocks.
On the subject of security and general atmosphere, we have a long history of security settling in fairly quickly to our lot's chilled attitude where we just want to have a good time without trying to ruin someone else's. Security from campsite into the arena is usually the most intense, but try and cut them some slack if they stop you bringing something like drinks in. Say hi to them, have a laugh with them, chuck a thumbs up or horns to anyone in a high-vis. Have a chat with them if they're looking a bit bored. Showsec guys work fucking long hours (and last year's heat was brutal for them), usually wearing the same shirt on Sunday that they were Thursday. Litter pickers through the day are our heroes. Festaff are often given long hours at lonely posts. When it comes to the rest of us Great Unwashed, look out for each other. Don't be afraid to strike up conversation in a queue, around the arena or around the campsite. If someone looks to be struggling, make sure they're alright. Keep a note of Lost Property at the Rock Society tent as well as the Welfare tent in the arena.
Set times tend to be released less than a week before the festival so keep an eye on facebook and this site. Set time changes do happen so keep an eye out in the arena and bring a pen to mark them out on your printed sheets (print out backup copies).
Make the most of your weekend. Have an excellent time.
