It could be either. It all depends on how much time and effort you're willing to give to make the dream come true. The Star says "this dream/hope can come true...but only in the future and only if you keep your eye on it and don't wander off." That's a big "if" for most people. We all lay back, gaze up at stars and dream big dreams. Having money, fame, marriage to this or that person...but all too often, what those dreams are really about is someone handing us these things, gratis, tomorrow. Some rich relative will leave us the money (tomorrow), some YouTube video we uploaded will go viral (tomorrow) and make us famous, and the person we want to marry will (tomorrow) look at us and decide we are their one true love. We will gain it all, in no time at all, and not have to do a thing.
One of the most important things a reader of Tarot must understand is that very, very few of the cards in the deck promise us a quick, instant, and easy change in fortune (Wheel of Fortune is one of the few, in fact, that says things will change for us just because).
The Star is one of those that promises us what we want, but only with time and dedication. When we get the Star card, we should image that we're like the captain of a ship in days of old. We're at sea, out of sight of land, with no idea of where we are. But there is a star in the clear sky by which we can navigate. Will it lead us to land? Yes. But we have to keep our focus on it, keep on sailing, and be willing to get there when we get there. If, at any time, we get distracted, say, "I think I'll follow those dolphins instead..." or if we give up, "This is taking too long/it's too hard, I'm going to try something else..." then we will not get there. It's as simple as that. Your dream requires that you keep that star always on the horizon, and never turn your ship away from it.
If you can do that, it will come true. If you can't, then "huh, you wish!"