Sheyne,
You definitely want to get tickets for a show. There is a discount booth "Tkts" and you can get tickets on the day of the show there. Choices will be limited but it is all about the experience of seeing someting on Broadway. You've got to do that.
Between now and then, you might want to watch some movies filmed in NYC and then you can visit various locations. Off the top of my head, and in no particular order, I can think of "Midnight Cowboy," "Breakfast at Tiffany's," "Hair" (good scene in Central Park at the beginning), "Elf," and "Tootsie."
Brand new, "The Devil Wears Prada" has lots of scenes of NY. Half of Woody Allen's movies fit the bill, too. "An Affair to Remember" has the famous Empire State Buliding scene. "Serendipity," with John Cusack; "Splash," with Tom Hanks and Daryl Hannah (just watched that a few weeks ago, oh so sweet). "Kissing Jessica Stein" has some nice views of NY, too. The opening sequence of "West Side Story" and scenes filmed on location are all in Hell's Kitchen (I believe). All those buildings were torn down soon after the movie was finished to build Lincoln Center, which you can get a nice view of in "The Producers" and "Moonshine." "Working Girl," another fav of mine, also features NY and after seeing that, you'll want to ride on the Staten Island ferry.
That should keep you busy for awhile. LOL.
Leslie