Nope! If you want to explore the area, then by all means rent a car and explore away. But, with the shuttle to and from the Reno airport, two restaurants on site, a pretty well equipped rec center, golf course, and plenty of nature, you're likely to stay plenty busy without leaving the resort.
It's fall in the Sierra Nevada, which means it'll be v pleasant during the day (mid 60s) but will definitely get chilly at night (mid 30s). As always when traveling in northern California, bring layers!
Please don't. Our lives are fairly hectic right now, and your being present is the most meaningful thing you could give us! If you want to get us something, please contribute to something on the registry!