Banish and cleanse. That’s almost guaranteed to be a parasite pretending to be something it’s not in order to get a free lunch. Go back and fix your spiritual hygiene BEFORE calling any entities. There are methods to ensure you don’t get impostors and you should use them and be very clear with your intention and ability.
You have free will that Lucifer respects as a higher being. Tell him to leave and mean it, if “he” doesn’t go attack it and kill it. Then call the real Lucifer. It’s that easy.
This is a very common newbie problem - we have many tutorials to deal with it.
Do not. You make yourself weak. If you get scared don’t do this magick until you feel stronger, and have better experience, you are asking for trouble
Again the real Lucifer would already understand and be gone - only parasites are pissy little bitches about it because they NEED you to feed on. Kill the stupid thing and learn how to do it right next time.
The real Lucifer will not help you because you got yourself into it, and minor parasites are actually easy to get rid of with a little attitude.