No sign of my private keys in Electrum wallet ... where do I find them?
You ask a lot of things, so I'll explain how Electrum works for you and hope it is what you need.

Electrum uses a seed (twelve words length password). Your private keys are derived from this seed every time you make a transaction.

The only thing you need to spend the coins received in your Electrum addresses is that seed. You can export the private key for one of the addresses in your wallet, but you should not do it. Keep your Electrum private keys PRIVATE.

You can also import a private key from another wallet, e.g Blockchain.info to be able to spend the coins in that address. It will be added to your wallet as a imported address, imported addresses behave kinda different to Electrum seed addresses. So keep a copy of the imported private key, just in case.

You will always be able to restore all your Electrum addresses using your seed, but not the imported keys, as they are not on your seed.