On topic I would say none of the advice given is bad. As said, you really need to trust the people you are tripping with, that's always an important part in a good trip. Also make sure you're in a good mindset overall. You can obviously tell if you're in a good headspace or a bad one. Try not to be nervous, I've always made sure to be respectful about chemicals (never being stupid about them) but not afraid. I feel that fear is something that's a pretty big cause of bad trips, people just feel afraid that they'll have a bad trip or get worried about something that's already bothering them a lot and get stuck in a mentally bad place. I've seen it happen. To be completely honest if you're in a trusted group and are being smart and not heroic on your first few, you should be completely fine almost anywhere that's not completely shady. Daytime I find is generally better to trip in, but at the same time night time is more convenient in relation to avoiding people. As already mentioned, if you plan on being outside make sure to have a warm and nice place to go, this could mean a friend's house or it might mean a fricken McDonald's or a Wal-Mart. Not that public places are the best, but if you generally feel that you're not going to be completely blatantly obvious or ridiculous then it's a good place to warm up and have a change of pace. Just my one cent.
. Camping sitting round a bonfire always seems to work for me!
. We will all be assigned to bring different drugs.