Can I talk to my fiance after engagement? Like chatting on mobile phones? And also can I go out with him? Qhat are the rules in Islam in this regard?

Before the marriage formula is recited, even though they have committed to marry each other, because they are not mahrams to each other and their looks towards each other is different therefore other than in very important situations, they should not have conversations with each other or meetings unless a nikah whether it be temporary or permanent is recited