Welcome. 16 plugs can be daunting. I did mine a short time back, though I have 10 less plugs, not quite as daunting.
Other checks and changes may include often overlooked or not service near the recommended time or miles. Diff fluid, coolant, brake fluid, transmission fluid, transfer case fluid, and front suspension bushings, tie rods, drag links. Just as you get time to do a once over, shake everything down, as you get time and cash.