Posture

A couple of things I think you will find helpful, in holding the guitar and feeling more comfortable, are to know that:

• When you hold a guitar have the fingerboard and the neck slightly pointing up. You do not want the neck pointing at the floor, because this will mean you will have to hold the neck up as you try and play.
• You should also raise your right leg up slightly, or your left leg if you are left handed, but your right leg up slightly - either on a footstool or just rest it on your left foot, or on a book, or whatever. This will bring the guitar up on your body a little bit higher and make you feel a little bit more comfortable.

You should be able to take your hands off of the guitar and it should sit quite comfortably, almost resting underneath your right arm. You will also notice that, posture-wise, my body is aiming this way but the guitar is aiming that way [headstock and neck of guitar pointing away from the body at about 30 degrees]. In other words, do not sit with the guitar too straight or else you will not have any space behind the fingerboard of the guitar for your left arm and elbow. You need to keep the guitar pointing in that type of direction [headstock and neck of guitar pointing away from body at about 30 degrees].