If you are just learning to play here’s a very basic concept that will help you. The guitar can be awkward to hold and play at the same time for most beginners. After all if you're busy holding the neck up with your left hand (to balance it) how are you going to use your fingers effectively to fret the notes? I see most of my beginners doing this until they are taught to take a different approach.
The key is to learn to balance the guitar without using your left hand. In the sitting position your right forearm rests on the top of the guitar naturally. The cutaway of the guitar sits over your right leg. So use these parts of your body to balance the guitar without touching it with your left hand. When you do this the neck should be nearly perpendicular to the floor, with just a slight angle upwards. This way when you add your left hand your wrist bends slightly to help your fingers fret the notes.
Practice balancing the guitar like this before you add the left hand. Once it is balanced try to maintain its position so the left hand is used only to fret notes, not aid in balancing the neck. This may feel a little bit different if you have been playing while using your left hand to balance and it has become a habit. But it is actually much easier to play in that position so it should be a good kind of different.
Before long you'll be comfortable with it and it will become second nature. Have fun!