I would recommend finding a local class to start with- talk to the teacher and explain you are a beginner. If you are set on starting at home, try looking up Adriene Mishler on you tube – she’s an American yoga teacher / motivational speaker and doesn’t take herself too seriously. Hers is a free channel and she has a wide range of videos including a number of 30 day programmes. I’ve done yoga for ages and find her the best ‘remote’ teacher, but I feel that for beginners you need someone to set you right in person!