When I went there a couple of years ago there were plenty of street-side stands selling old full-face helmets for super cheap (like 200nt). They might stink a bit, but they’ll protect you well enough. Don’t forget to tape a towel or something all the way around the base of the helmet, to protect your neck and shoulders - you will hear stories of rockets shooting up into the helmet, you want to be sure that doesn’t happen to you.
For the rest of the gear, I was wearing thick scooter rain gear, and that worked fine. Some people also built themselves an “armor” out of cardboard boxes, it worked pretty well. You’ll want to wear gloves too. Basically, don’t leave any body part uncovered, and go for thick, sturdy clothes.
I’m afraid I don’t know anything about accommodation there.
Do the fireworks fly around everywhere, just in one spot, or does that spot move around? I’m getting my gear together. I’m just wondering if you’ll need the gear when going into the middle or a certain area or in many places?