is 'vien' necessarily followed by de

Bonjour Diana, It depends on what you're trying to say. When you mean "to come from" or "to have just done something," yes. I'm coming from a restaurant - Je viens d'un restaurant. I just ate - Je viens de manger.

But in other contexts, you could simply use "venir" on its own: I'm coming to see you - Je viens te voir. He's coming to my house - Il vient chez moi. etc...