You can lose weight as long as you don't eat too much exercise. Some yoga moves must be done under the guidance of a professional teacher, otherwise it will be harmful to your health. However, all the online videos you can find are safe and you can practice at home.
Some yoga can lose weight, while others just relax.
I'm practicing Guo Jian Hu Haiyan's diet yoga bean list at home now. It's very good and famous, but most of them are in Korean, and you have to watch videos to practice yoga.