In general, doing stage door before a show isn't really done. It's just the convention, especially given Equity rules about actors being signed in by a certain time or they risk penalties. I wouldn't personally recommend it. It's not "stalking" but it's not considered very courteous. Many actors have reasons (personal stress, vocal rest, sheer preference) that they don't do stage door, and you should respect that.
That said, I have, once or twice and by sheer accident, run into actors before a show. Once, I forgot to take a marquee picture when I saw the show, so I walked back up the next day to snap a picture, and when I turned around to leave I almost ran smack into one of the actors arriving (who hadn't come out the day prior). I apologized for not watching where I was going and thanked him for the previous day's show, and he couldn't have been kinder - shook my hand, chatted for a few, apologized for not coming out (which was totally unnecessary) and offered to take a picture then and there.
But I can't stress enough that that was an accident, not me waiting with that express purpose. It was obvious I'd been taking a picture and walking, not hovering by the door. And many actors may not want to or have time to speak before a show, and it's not considered a convention the way that post-show stage door is. I understand wanting to meet an actor whose performance has meant something to you, but I would encourage you to stick to the usual means and be polite.
Updated On: 7/27/17 at 02:29 PM