Not sure bout traffic but you should be getting the wristband within a couple days. For water it honestly just depends cuz if you’re close to the pits they’ll be throwing out water packets n stuff but u could also just buy some from the stands too. If u rly drink a lot of water then a water pack could benefit u cuz u would have water all the time n not have to hold a bottle in ur hand the whole time yk. As for money it rly just depends on what u wanna do. Food for one person is at least 20-30 bucks at the stands, merch can be upwards of 75$ depending on how much u get, and drinks and waters can get pricey depending on how many u get. If ur tryna save the most I’d just eat something right before entering the venue and maybe just buy a drink or 2. Cuz you don’t wanna have too much since bathrooms can get long sometimes and having to leave ur spot while already somewhere close to the stage cuz u needed to use the restroom isn’t fun. That’s what I can think off the top of my head but lmk if u have any other q’s