Well, this may spark some outrage, but I would send the entire thing back. The more you tinker with it, the unhappier you will be.
I just recently got into O gauge trains, and I have not had any problems because I only buy, piece by piece, the used, old school, post war engines and cars, plus the best, new or close to new, 3 rail tubular track I can find, but only Lionel and K-Line. It is a really cheap way to get into this hobby slowly, and you learn as you go.
By studying each piece in advance, asking questions from the many helpful people on this board in advance, and then asking detailed questions from the Seller in advance, I have avoided having any real problems with anything I have purchased, save for a few standard old-type mechanical repairs that took only minutes to fix.
You may think that this would take months and months to get a complete train set, including engines, track, switches etc., but I was able to acquire everything, including two good working engines, a good transformer, tracks and switches, and a dozen nice cars, in about 4 and half weeks, for around $400. The vast amount of it was bought on Ebay.
My layout is large, it is 9.5 feet by 5 feet, and has three separate train routes on it. (The cost of the lumber was an extra $90 or so.) I just bought the Lionel Gateman and Shack accessory, which was old but works fine, in the original box, for $5.00 plus $10.00 shipping on Ebay. (New ones go for as high as $50.)
The engines I bought were a 1950s, cast iron, Scout locomotive, for around $55.00, which works great, and a 1970s, plastic Lionel Diesel, for around $10, which also works great. (I got the second engine for a steal, but you can find them online for as little as $25.)
If you are paying primo dollars just to get a cartoon character train such as the Polar Express, just for you kids, then you may consider rethinking that a little. The "cartoon" attraction of the train will very soon fade with the kids, and they will very quickly move onto other cartoon type things. With my grandchildren, I am going to buy each of them a cheap 1960s or 1970s, plastic Lionel diesel engine, and then let them paint it any color they want, including putting their names on it in decals. They can each run their train any time they visit, and assuming they don't burn them up, they will all have keepsakes for the future.
Go slowly, check Ebay every day, ask lots of basic questions on this board, use the free subject search feature on this board if you are a member, and you will soon have a great set, low frustration, and few problems.
Mannyrock
