I agree with Thijs, save your money and get on a train. It's only a short trip, but I think even with a big bag, the best solution.
Last time in Amsterdam I had really lovely dinner at the Kop van Jut, and very small restaurant near Leidscheplein, (Leidsekruisstraat 24). not too expensive, and yet good food.
If you like art, and the paintings by van Gogh, the van Goghmuseum is a must. As the centre is really small (compared to other cities), you can do everything by walking around.
Don't worry about looking like a tourist in Amsterdam, most of the time I have the feeling that everybody in the centre of Amsterdam is a tourist, or at least half of them.