The first account I have is a native segwit with a derivation path of m/84'/0'/0' while the second is a nested segwit with a derivation path of m/49'/0'/0'. If I am going to create let's say for example another nested segwit account using ledger, is it correct that I am going to change the path to m/49'/0'/1'?
Yes, that should do it.
m/49'/0'/1' will derive the addresses/keys for the second account.
Also, I accidentally created a duplicate account with a same derivation path of the nested segwit account I have and fortunately I did not encounter any issue in deleting them since it is just a duplicate, that is why I want to verify if changing the derivation path to create another account is the correct way in doing this.
That's because Electrum won't automatically create a wallet based from the second or next accounts if you try to create another one unlike Ledger live.