Wireless mic recommendations?

Can someone walk me through this wireless mic setup?
Like, what’s actually doing the heavy lifting when it comes to playing back the audio??
And where am I supposed to plug in the receiver?

It’s basically your amplifier paired with the speakers that you plug the microphone receiver into.

ps:
You just gotta double-check the specs to see what frequency it runs on so you don't run into any interference. Like, if the range is sitting somewhere between 87.5 and 108MHz, you could actually pick up local stations like ESPN Radio through the amp. It would work on pretty much any standard radio.

Aha, okay.
Let me know if you happen to know what this
is. What's that little box thingy attached to the mic?

That "box" is basically just referring to one of those action cams, like a GoPro, which you can pair up with that condenser mic they sell.
You can plug it straight into your PC, too, but if you use that little adapter with the micro USB, you can hook it right up to a GoPro.
The whole "omni" thing just means the mic picks up sound from every direction—it’s not a directional mic that focuses on just one spot.