Recycling some tips I wrote in a previous thread, but hopefully, some of this should be helpful.

General useful info:

• Bring earplugs, sometimes festivals will provide them, but just in case it might be good to get your own pair.
• Get to stages early. usually, security will let you into the photo pit 5-10 minutes before the act comes on stage, but may not let you in once they’re already on.
• Stepstool. Depending on the height of the stages you may want to bring a little stepstool to help you get some height. Note: Worth checking with the festival that they’ll allow you to bring it in before Friday if you do want to bring it.
• Be mindful of others. Pits are busy (security, other photographers, band crews etc etc), keep an eye out you’re not blocking other people’s shots when moving around, stash your bag under the barrier, don’t put your camera on the stage.
• Drink water, eat some food. It’s so easy to forget if you get into the swing of things, running about a festival with a camera trying to get to things on time, so when you do get some time do some self care.
• Wearing black (or darker neutral colours). Again just general courtesy to the bands/other people working around you, bright colours are distracting.
• Depending on the size of the festival there may be a ‘press tent/area’ you might have access to to drop off bags, take a rest etc, so might be worth checking the festival has this

When shooting:

• On the lenses, it really depends on the size of the festival. If it’s smaller, bring the 18-55, if it’s bigger bring the 55-200mm. If you can find a way to bring both, bring both and stash one in a bumbag or something for easy access to swap around when needed. If the space issue is because of the festival’s bag policy, they’re usually waved for photographers with a pass (check with the festival if this is the case beforehand as every festival is different.
• Settings-wise, honestly, there’s no hard and fast rule with concert photography. But the I Shoot Shows blog has some really good guides on settings etc if you’re unsure, so I highly recommend checking that out.
• Phone-wise, some festivals can be a bit fussy about phones in the photo pit, so check with them it’s okay to use if you do want to do that
• Experiment, from what you’ve said on the thread you’re there mainly for fun. Don’t stress yourself out trying to get the perfect shot every time. As someone who’s been doing this for years, not every photo will be perfect, or even good, you’ll be lucky to come out with more than a handful per set. Figure out what works for you and what you like. I recommend at the end of every day import your photos somewhere and have a look through to figure out what you think works and what doesn’t and use that to learn for the next day. If in doubt ask other photographers, we’re (mostly) a very friendly, if not shy, bunch.

Hope you have fun with it! And any other questions pop them below

Good things to keep in mind if it’s your first big show:

• show up early, you’ll need to go and collect your accreditation from the guest list. After you’ve collected it may need to be escorted to the photo pit by security, so it’s always worthwhile asking whoever’s giving you your pass or venue security where you should go as every venue has it’s own rules and setup when it comes to dealing with photographers. (note: it’s not uncommon for large venues where in the UK to make you wait outside between bands, might not be the same where you are, but it’s worth being aware that may be a possibility)

while shooting:

• be mindful of others, don’t stand too long in one spot, make sure you’re not getting in other people’s way etc.

• One thing you may want to look at is getting a little step stool to get some height as if it’s a large venue the stage might be awkwardly tall, but if you do bring one check with security before the show to see if you’re allowed to use one.

• getting everything in that timeframe: It’s difficult but doable, from memory neither band moves too much during first three so you should have plenty of time to think through composing your shots. Interpol will most likely have a lot of red lighting while you’re shooting (or at least have had in the past), Bloc Party were bright white lights last time I photographed them, but that was years ago. If you want to get an idea, have a look at getty’s photo feed (look up the band name and sort by newest) as they tend to have a fairly up to date library of images and it’s unlikely lighting will change too much from show to show at that level.

• after the show: since it’s a first three no flash rule, it’s very likely that you’ll be escorted back out of the venue, and won’t be allowed back in unless you have a ticket and/or are checking your camera gear in. Again, this is dependent on the venue etc, but if you do want to stay for the show it might be worth asking your point of contact if you could also get a ticket if you don’t have one already

In terms of if it’s worth trying to get on stage, unless the tour manager has said otherwise, the pass you’ve been given will not allow stage access. And to clarify that "nothing from front of house/crowd after the first three” - front of house generally encompasses anywhere in the venue after the barrier (aka where the crowd are), so that means you won’t be allowed to take photos from the crowd/back of the venue

Any other questions feel free to ask. If you haven’t yet I highly recommend checking out Todd Ownyoung’s blog, I Shoot Shows as he’s spent years putting together loads of helpful tips for shooting concerts