I just ordered my Ledger Nano S and it will arrive in few days.

1) My question is, let's say I have 1 BTC in my Ledger Nano S, and I plan to sell 0.2 BTC on exchange. So I send 0.2 BTC to say, Coinbase. Where will the remaining 0.8 BTC go? Will it stay in the same existing address in hardware wallet or will it store in another address in hardware wallet?

2) I am currently using electrum mobile wallet to store my bitcoin. If I send all bitcoin from Electrum  to my address in Ledger Nano S, will I see Bitcoin Gold and Bitcoin Diamond in my Ledger Nano wallet?