And another question if in this case I specify an internal address or addresses when transferring, will that be okay?
Yes, that will be okay. Bitcoin does not make any difference between addresses (of the same type) when you make a transaction, regardless of whether it is an address from your wallet or from someone else - the transaction will be the same. You can even send bitcoins to the same address they came from. This is what some people do when consolidating smaller inputs when network fees are low.
Or maybe there is another way to transfer internally from address to address or from addresses to address or from address to addresses?
Thanks.
There is no other way to create
an internal transaction with the Electrum wallet, as far as I know. But there is a way you can simplify the process of creating a transaction with selected UTXOs.
First, copy the address where you want to send the coins to the clipboard. If you are sending coins back to your wallet, copy one of your addresses from the Addresses tab. Then, go to the Coins tab and choose the transaction outputs you want to send. (Use Ctrl+click to select multiple outputs.) And lastly, right-click the selected UTXOs and select "Fully spend > send to address in clipboard." Electrum will automatically prepare a transaction with all the necessary information filled in. Before sending, double-check that the destination address is highlighted in green (or orange), indicating its part of your wallet. Then, review the transaction details and confirm it.