I have had many a frustrating moment like that myself, and know exactly how you feel. Now you've got new gear though, it would be worth going out and practising with it so you get a feel for exactly what it is and isn't capable of. It'll also make sure you're as good as possible at getting the most out of your camera.
I don't know much about your experience, so apologies if this is old news to you, but I keep my camera set to Av (and the widest aperture) so I can get the fastest shutter speed, adjust the ISO so the speed is good and quick (but watch out for noise above ISO 400), and autofocus to AI Servo. Make sure you've also got metering on 'partial' to get the best exposure. Then I go to the nearest seaside town and shoot flying seagulls (with my camera, not out of frustration!). If you're impatient, buy a bag of chips to lure them in
Hopefully this will help you out a bit! But dont' get too stressed, the more you do it, the better you'll get. It'll come eventually, just enjoy it!