Agree with SeaSteve. Based on that description, I would not be concerned about oil pressure. The system is behaving as designed. It sounds like you also now know why she would not start (sidestand).

The only thing left is why it stopped originally. Agree on checking battery, but I would not expect it to "heal itself" and restart. Given that you are still getting used to your new-to-you bike, is it possible that you accidentally booted the kickstand while riding at 40mph?