clarify what is it that you have exactly?
is it an Electrum Seed? if yes, is it in readable words or is it encrypted (protected by password)? and do you know the password?
is it an Electrum wallet file? if yes, does it have a password? and do you know the password?
is it an Electrum wallet file but you imported the keys in it instead of letting it create a new wallet for you? is this wallet encrypted and do you have the password?
basically you need to open your wallet in Electrum, copy private keys of each addresse that you like (you can use the filters to filter ALL and Used then right click and copy).
if you want to use console then go to the Console tab and type these codes in:
this will give the list of all your addresses that your wallet is currently showing. copy the result with the brackets and:
getprivatekeys(_Paste_Here_)
paste it where it says _Paste_Here_. so it would look like: getprivatekeys(['1aBcD....', '1AbCd...., ...])
this will list all the private keys of these addresses for you.
in the last step you will be asked to enter your password if your wallet was encrypted.