NBitcoin is only a library. In order to get notified upon receipt of funds you would need to be running a bitcoin implementation such as bitcoin-core and use it's JSON-RPC, or ZMQ or it's built-in features like walletnotify.
How do I use walletnotify?
Dont check the 'Make blank wallet' option when creating a new wallet.
Blank wallets don't initially have private keys or addresses, those can only be imported. Having the new wallet encrypted or not has no effect on the ability to create a receiving address.