Smoker (BBQ) thermometers are not generally very reliable. More just something to look at.
What Jared is referring to is something like an
instant read thermometer probe poked into thick parts like the breast meat of the bird, if doing a whole bird. They are nice to have, but not a requirement to start.
If your BBQ is like in your Avatar, it is a dual fuel? Looks like an offset, with a propane option.
Maybe your best start would be to do parts first to begin learning. That way you can move and remove as things get done, instead of a whole bird at once.
I remember my first time cookin (Besides hot dogs or hamburgers), and it was chicken legs and thighs. Hot as hell 4th of July. I just kept turning the parts, and if some looked doner than others I'd move things around. But I kept turning and moving, and finally sauced and pulled when the sauce looked cooked on.
I guess it must have turned out OK. I never got to taste any. By the time I got around to getting me a plate, there wasn't a damned piece left. I was told it was good...
And that was my first real experience at Bar-B-Que'in. LOL! Not a good one, but one I'll never forget.
You can start off with SPOG. That's Salt, Pepper, Onion Powder, and Garlic (powder or granulated). Amount I'd recommend would be about the same as if you were sprinkling it on food on your plate. If you don't have one or another of those spices, it's OK, just go ahead without it for now. But SPOG is a basic you will want to have around when you can.
If you don't have a BBQ sauce around, you can check for home made sauces here or on the web. Or just never mind sauce. It could be as simple as Ketchup with a dash of vinegar to taste.
Eventually you will find seasoning you like on food and begin to develop your own favorites.
Always cook your chicken to done, but not dry inside.
I prefer to use tongs (long ones) when I'm grilling. Longer tongs help keep your hands back from the heat. And tongs don't poke holes in what you are cooking to let the juices out.
Smoke on towards the beginning, or the whole time. Then adjust the temperature with the propane if needed.
Don't expect too much of yourself, you are learning. If it isn't great, it's OK. Next time will be better.
Use Pecan wood, or hardwoods found in your area. No softwoods.