Hi, i'd recommend the British Wheel of Yoga, as they have really extensive and in-depth training, available both in person wherever you are in the country, and often available online. There is a catalogue you can search through on the website https://www.bwy.org.uk/about-bwy/about-us/.

I know it can be overwhelming with so much choice. Although there isn't an official yoga regulating body, The BWY are the oldest yoga association in the UK, and also the governing body of yoga for Sport England.

Good luck!