There is a tonne of info about this sort of thing out there so be sure to check.
Having said that, there are a few things to do first...
the 18MP APS-C sensor picks up a tremendous amount of detail. Because of this it requires extremely high quality lenses and extremely good technique on the photographer's part. I suspect that your kit lens just isn't up to the task. If you have a higher quality lens (macro, 50mm prime etc) put it on the camera, stop down to f 8.0 set up on a sturdy tripod, get good light, use a cable release or timer and take a few pictures. This is your starting point. Each of those items you want to change (not using a tripod etc) will mean that your technique will need to be up to scratch.
Also, birds in flight are very hard subjects at the best of time with the best of equipment. You need to try something a bit more basic before you judge anything.
Good luck. There is a reason this camera is not marketed to beginners. It really does require some solid skills.