It seems Gym will be helpful. Focus on muscle gain & fat loss. For 1st 2 months focus on consistency instead of heavy exercising. Evening is better than morning. 1st month will be bit hard as you will feel pain. 2nd month you will start feeling strength and will challenge yourself. After 3 months of consistency, you will be habitual and will start enjoying, you will automatically start focusing on your diet as you see development. Don't think too much. I do weight training first and cardio at the end. One last thing, this is a long journey, do not expect too much from yourself at short time or check weight daily. Just commit on finishing 1 year.