What you might want to do, for starters, is put the camera on TV and take a few pics. Use speeds of 60-200 for things that don't move, a little faster for things that move, and 1000 or so for things that move fast. That's just a start.
Shoot in Jpeg at the beginning, and then move to RAW later.
Mostly have fun, and don't worry at first if the pictures aren't what you think they should be. Almost every single person, upon getting his first DSLR, questions whether it can outperform a point and shoot. The truth is that the DSLR, once you get the hang of it, will beat any point and shoot.
Don't forget that you can rent really nice lenses, both online and probably locally too (online is usually cheaper). If you order locally, take advantage of holiday weekends and Sundays so that you can get two or three days for the price of one.
You'll want to rent the 100-400 for zoos, airshows, sports, etc. in good light, and then you'll find that rentals are fun and productive.
The nifty fifty they're talling you about is a great lens. I actually don't use it much, but for portraits it takes incredibly sharp photos. It's just not very good for action shots.
This is a Brazilian surfer at a professional event last year, taken with the XS and a 100-400 lens I rented.

Another shot, same day, of pro surfer Rob Machado. He made it through this maneuver and kept going. Great surfer.
Thank you. 