Pellet grills make backyard BBQ more approachable, but they do not eliminate the learning curve. The first mistake is thinking the controller temperature tells the whole story. Weather, wind, lid openings, meat size, and where the probe sits all matter.
The second lesson is patience. Bark takes time. Fat rendering takes time. A pork shoulder might sit in the stall longer than expected. If you wrap too early because the clock is annoying you, the final texture usually tells on you.
A good thermometer is not optional. Guessing internal temperature is a fast way to overcook steak, undercook chicken, or pull pork before it is tender. Temperature gets you close; feel tells you when you are actually there.
The biggest improvement we made was writing notes. Pellet choice, outside temperature, grill setting, wrap time, rest time, and final result are easy to forget after everyone starts eating. Those notes turn a lucky cook into a repeatable recipe.
Beginner BBQ gets easier when you stop chasing the clock and start watching the food.