Are you saying you just want the experience of waiting on a line outside in summer for hours, or you want the experience to wait on line to get a specific spot inside?
If you are arriving between 12-2 that is still a fair time to be considered part of the "fan-run" line. Also, there will be people enforcing the line, so if you don't get a number you may end up getting sent to the end of the line when it's time to go in, and you will be no better off than what you have done in the past. Make nice with the people around you, you'll be spending a few hours together! We have to take care of our own! Between getting your number and becoming familiar with the people who are around you, this will 'secure' your spot as much as you can for a completely unofficial thing.
You can come and go to an extent - try to always have one of you on the line, or tell your line-neighbors you're stepping away. But don't vanish for hours. And try not to leave in the last hour or so before the doors open as you never know when the venue staff will want to start condensing the group and barricading you in.
Depending on where your venue is will have a lot to do with your options - for example - MSG is in the middle of Manhattan with plenty food options (and real bathrooms in Penn station!) you can walk to. But Uniondale was in a somewhat remote area, so bringing your own food was necessary.
Stay hydrated, eat a full lunch and/or dinner otherwise you will be hangry, use sunscreen, bring hand sanitizer as the portapotty situation isn't always going to provide a proper hygiene scenario. Also I bring a little extra toilet paper too just in case you can obviously discard once you're inside/don't need it anymore. It's kind of like camping/picnicing...
I know this sounds like a lot but it's not rocket science I promise.