I do mostly birds on my rotisserie. Have you done a whole chicken yet? I'd start with that. It will help you feel comfortable making sure you have figured out the prep (brine & rub, and their timing); the temperature (which burners, on what heat); and the cooking time (more on that below). On my old Weber Genesis, I find it actually takes a pretty long time. This is not necessarily a bad thing because those wonderful Costco rotisserie chickens (just had one last night) cook for a long, long time.
I did do a turkey one time, and they take a LOT longer than the chickens, so that will be the one major adjustment. It's a little like the difference between smoking a 3 pound pork butt compared to doing the same thing with a 7-8 pound butt: it takes much, much longer.
No matter what technique I've used for cooking a turkey, it is never ready at the time I was shooting for, and it seems I am always off by at least an hour, one way or the other, not matter how much planning and reading I do. It will be no different with this.