Since you're starting out, I'd say stick with f1.8 (ish) primes.
You can get a Canon 35mm f2.0, 50mm f1.8, 85mm f1.8 and not spend more than around $800. If you buy Used, you can definitely get that for much less (and possibly within your targeted budget). You'll be a little limited on the wide angle end, but you'll be covered for your most popular focal lengths and be able to shoot in a wide variety of lighting conditions.
Unfortunately, there's just not really a "cheap" zoom option that also lets in a lot of light. That 17-55 f2.8 recommendation is the only real option, but you'll be spending around 2-2.5 times your budget on one lens that will be limited to just the wide angle and standard focal lengths, excluding a really nice 85mm portrait range.