There are differing opinions, but if you intend to go an to take wild quarry, a Harris' hawk is very user-friendly, robust, and easy to train and handle. You could also consider a redtailed buzzard, although they are slightly harder for a beginner. With any bird that will not generally catch anything its usefulness ends as soon as it is trained, whereas the Harris' or redtail will go on taking quarry and improving over months or years. AVOID anything small, like a barn owl or kestrel, and there is no margin for error with weight, NEVER think of the hard birds like goshawks, sparrowhawks or eagles until you are very experienced. Some of the middle-sized to larger falcons are relatively easy to train, but will ALWAYS need to be flown with radio-tracking equipment. You may be interested in owls, and some species can be flow successfully, and some will even take quarry. However, if it is your intention to fly at quarry you may be giving yourself a very hard time.