Here's a step-by-step guide on how to do squats:
Stand with your feet shoulder-width apart or a bit wider. Your feet can be slightly rotated out.
Extend your arms straight out in front of you to help maintain your balance. If you prefer, you can also bend your elbows and hold your hands together.
Hinge at your hips like you're sitting in an imaginary chair. Look straight ahead. Make sure your spine stays long. Keep your abdominals engaged to protect your lower back, and your chest lifted.
Lower down until your thighs are as parallel to the floor, your knees at a 90° angle. Make sure your knees do not go over your toes. Your weight should be in your heels.
Push through your heels and squeeze your glutes sending your hips forward to come back up to a standing position.
Check out this youtube video to visualize what your squats should look like.