Congratulations.
1) You can google for RV checklists--there are plenty on the internet. My advice is to have the dealer go through EVERY system in the RV and show you it working and how to maintain it (e.g. for the water system they should show you it on city water, on the internal pump and show you all the valves and fixtures used for winterizing it).
2) I've had good luck with Adco covers as sold at Camping World:
ADCO Covers