Doing a weight training (body weight or weightlifting) and a yoga program at the same time is a great idea! This way you'll get a more versatile workout regimen and also stretching and muscle toning/lengthening exercises besides weight training. I do recommend learning the basics of yoga first though, because none of the yoga workouts that I've tried on this app tell you how to get in and out of poses, which is really important, and they move forward from pose to pose very quickly.