Particularly for a first try, there's nothing inherently wrong. Good, clear focus and dealt with the nasty back lighting fairly well.
Things to watch out for:
- As others have said, consider the background/"things they're perched on" and attempt to minimize manmade objects *when possible*...this is highly dependent on location and cooperation of an uncooperative subject 
- Height/angle: As with other animals, belly/butt/"up the nose" shots are less than ideal in general. Making use of the long zoom to step back a little/lot to lessen the angle between you and your subject can help your composition quite a bit, even if that sometimes means framing a little looser and cropping in post.
- Eyes: It's all about "eye contact" when you're shooting sports/animals/birds. If there isn't a good line from the viewer's eyes to the subject's eyes, you've mostly got a "dead" shot unless you're going for something very specific in what the animal is doing, etc. They don't have to be looking AT the camera, but you want the eyes visible and clear.
- Lighting/angle: Overcast days are nice in that you don't have to be as concerned about your direction/angle to the subject; but, on brighter days, you want to be finding angles where your subject is "front lit" more than "back lit". Side light can work for/against you and has to be evaluated on the fly. I generally use my own shadow as sort of a compass; if I can point my shadow directly at my subject, that is the best angle to shoot from. If I can't, I'll get as close to that position and I can and then adjust exposure for those conditions. Also, try to get on their level as much as you can; shooting straight across vs at a steep angle gives a much more pleasing angle to the eye on your subject.
- Try to find them "doing something" whenever you can. There are a ton of perching shot opportunities and these can still offer great results; but the truly outstanding shots will contain some sort of action or convey a bit of "personality" in the exercise.
- As for "what" you got here, it looks like a female Ping Grosbeak to me; but, I'm not an expert on the Passeriformes, by any stretch. For getting IDs answered, it's always important to include location and season with the request as those can be key factors in what is around any, given location.
Pigpen101 wrote in post #18986234
How does the version II hold up to the 400mm F/5.6 (if you know)? I'm looking to use this lens to replace my 70-200mm, & 400mm for football games.
By all accounts, you get the AF speed of the 400 with all the other benefits of the zoom; much shorter MFD, IS, better glass, varied focal lengths and it's roughly the same weight, I believe.