Midnight, if this is your first layout, you might want to start out with something a bit more basic. I'd suggest a shelf-type switching layout. You could put it along one wall in your bedroom, and your benchwork could be as simple as some shelf brackets and some shelving. You won't need a lot of track to get started, and a switching layout will give you enough opportunity to run trains, build some scenery, and assemble some structure kits. Or, try your hand at scratchbuilding. There are lots of plans around for industrial or urban-style layouts, and you can add track (and all the other goodies) as your budget allows. Birthdays and Christmas are also good opportunities to acquire new train stuff. (If you have a choice, go for gift certificates: that way, you can buy the stuff you really "need".)

I had my first layout when I was 8 or 9. It was a 4'x8' that my Dad built, and was a lot of fun to run. When I moved out, we had no room for a train layout, so it was sold. I built a couple of dioramas, but it was a few years before we bought a house, and even then, there wasn't much money for trains. Eventually, I built an around-the-room layout in one room of our basement, but it was never finished. When we moved, it was left for the new owner. A couple of years later, an opportunity arose, and we were able to build for ourselves a new basement (with a house on top for the rest of the family). The layout that's here in the basement now, after we've been here 18 years, occupies a very odd-shaped room of about 600 square feet. You may have seen some photos of it here on the Gauge, and if so, you'll have noticed that it's not done. In fact, there's more unfinished than there is finished, and I'm about to start building a second level.

My point, if I can remember it, is that the only "finished" layout that I've had, in over 50 years, was the first one, and it's gone. Your tastes in trains will change as time passes, you may leave the hobby for a while (girls, school, girls, cars, girls, work...all interrupt and when you come back, your interests may be different.) Don't try to start too ambitiously until you discover some of the things that interest you most about trains. And read, both books and magazines, and here on the Gauge. There's tons of stuff to learn, and lots of willing teachers here to help.:thumb:
And finally, a small suggestion: I don't know how your relationship is with your Dad, but perhaps if you offered to lend a hand with the chores, either through the week or on Saturdays, it might give you a chance to talk with him a bit about your plans, while at the same time helping to make his day a bit easier. He'll be pleased that you're thinking of him, and maybe be more receptive to your point of view.
Wayne