Allah only forbids you to make friendship with those who fought you on account of your faith and drove you out of your homes and backed up others in your expulsion. Those who will take them for friends are indeed the wrongdoers.
Meaning:-
Forbid: Prohibit, not allowed, banned.
Expulsion: the process of forcing someone to leave a place.
Wrongdoer: criminal, a person who behaves illegally, or dishonestly; an offender.