I can only speak of my experience, but in the parish I usually attend, when venerating the cross after liturgy, people are free to talk to Father for a moment, or ask him if they can speak with him after he has finished with everyone. Then you just sit in a pew and wait for him to get done, and then he can meet with you for whatever reason, or set up a time to meet later if you need to talk at length. I usually just say "Father John" or "Father," and usually don't ask for a blessing or kiss his hand* because I've never seen anyone else at the parish do so. If your priest isn't usually available afterwards (e.g. at coffee hour), I'd say just be bold and, after venerating the cross, ask if you can talk with him for a moment after he's finished.
*Though I do kiss his hand after venerating the cross