My favorite lens for "just getting going" would have to be the Tamron 17-280 VC superzoom. It's light weight, covers most needs distance-wise (17mm is fairly wide) for most of what you seem to want, and their image stabilization (VC) beats any of the Canon lenses in the same price range, as far as I'm concerned.
It's a great way to have a "good enough" lens to figure out what you want upgrade to when you get better glass. And the IQ on this lens is absolutely nothing to sneer at, it's a good, sharp lens that just needs light at the long end. But you'll find that to be the same limitation on almost any zoom short of moving into the "L" line and/or price range.
Congrats on sticking to your guns on the T2i; I think you'll find you've got a very capable body there.
sir its Tamron 18-270mm VC