I think you'll be good. Put the two passive speakers in front of where the stage will be, one speaker on either side of the stage, facing the audience (don't put the stage in front of the speakers). Connect them with speaker cable to the mixer/amp. That's where they get power from. I would run it in mono. One cable from the mixer to the closest speaker, and then another cable from the first speaker across the front of the stage, to the second speaker.

You'll need to put those speakers up on stands. You can buy them, or rent them from an AV company. It's a must.

You probably don't actually need the sub, but i would put it under one of the speakers, but the one closest to power and the tech table. The sub needs power and a separate non-powered audio output cable from the mixer, so those runs should he short. There is a second non powered audio output on the mixer for the sub.

The mics will work fine. Keep the receivers within line of sight, keep singers behind the speakers on stage and you'll be fine.

When outside, try to keep cables out of people's way. Use carpets and cable mats in high traffic areas outside instead of tape. You can rent cable mats. Tape doesn't stick to grass and dirt.

Keep power connections up off the ground, so they don't get wet if it rains. Bag all cable connections up so you don't have to unplug stuff later to do it if it rains. I tie cables together outside so they can't get kicked loose.

Make sure the tech table is covered with a tent and have big plastic garbage bags ready to cover speakers if it starts to rain. I stick them in the handles of the speakers, so they're ready to go.