Hi,
If you want to build your muscles, yoga can't help you.
only through proper strength training, you can achieve that.
I suggest you, take a personal trainer (well Reputed gym) for 1 month and learn all the strengthening exercise in Proper way then you can continue your own self.
Next Steps
3 days/week for the gym( to sculpt your body) and 3 days/ week for yoga (for flexibility of muscles and mental health)
Health Tips
Are you suffering from any muscle pain or joint pain?
if so please consult a physiotherapist if not then you can start the gym and continue yoga.