The simplest and cheapest way to start is to buy a chicken or two. Now you could brine them or brine one and not the other to see which way you prefer, but you do not have to brine. You could inject them if you want, but again to be simple you dont have to. Just toss them on let the smoker do its work.
I do suggest you get a wireless temp setup. Put the probe in the meat and you can keep an eye on the meats temp without having to open the smoker and check temps. Resist the urge to open it every time to want to check on it, it isn’t like your grill you don’t have to open it every 5 minutes. Enjoy!