I applaud you for taking the initiative to better your health and fitness.
In my practice as a physical therapist, I utilize squats for clients regardless of their age or weight. The squat is such a powerful exercise that combines several muscle groups in the lower extremities and core. Lots of bang for the buck!
Having said this, I often find myself doing a lot of 'coaching' to ensure the squat is performed correctly. For if not, it can cause harm.
2 things to concentrate on: your form and the depth of the squat.
Form - Place a chair behind you and initiate the movement as if you were going to sit in the chair. To accomplish this, you MUST bend at the hips. Aim for the seat. Too many people bend only at the knees with this placing a lot stress to your knees as well as potentially overtaxing the muscles along the front of your thighs (quadriceps). You should NOT lose sight of your toes during the entire maneuver. Try to maintain tension in your abdominal muscles also.
You need not (and should not!) be preoccupied with how deep you perform the squat. If seated in the chair I spoke about aiming for, your hips will be positioned higher than your knees, perhaps significantly so. this will help ensure that you don't go too deep.
Final thoughts:
Lose the 10# weights for now. Body weight should plenty suffice for what you're hoping to achieve in this early phase.
I answered based on available knowledge provided in your question and with the assumption that you don't have any orthopedic issues or other contraindications for performing squats. Should this be the case, I would advise consulting with the appropriate medical professional to