The usual problem amngs beginners is that they hold the guitar to help them see what they're doing. That is the most frequent problem and the easiest to solve.
If you stand to play, don't have the guitar hanging round your knees. It may "look cool" in some circles, but it will not help your playing one iota. Get the guitar to a level where you can comforably fret the chords. Try setting the strap so that the guitar hangs at the same height as if you were sitting and holding the guitar on your lap.
Hold the guitar upright. Beginners like to see how well they are fingering chords, etc. and turn the face of the guitar upwards. This, of course twists the fretboard away from your fingers - causing a bent wrist. Try sitting in front of a mirror to see what you're doing and hold the guitar upright.
Another easy problem to sove is holding the neck too far from the line of your body. If you stand with your back to a wall, the guitar should run more or less parallel to the wall. If the neck is further from the wall than the body (the usual case), you're forcing the wrist to bend, simply to reach the fretboard with you fingers.
Have all those problems and you can understand why your wrist has to be so bent........................