Flying Crane
Sr. Grandmaster
Also find out how accessible the instructor is. If all you want to learn is a form and some simple chi kung then this may not be necessary.
a form and "simple" qigong? It doesn't exist. It holds a place in modern mythology right there along with the Easter Bunny, the Tooth Fairy, Leprechauns, and Santa Claus.
There is no form, nor qigong so simple that you can learn it properly and well from video alone. Even the "simplest" form has far too many nuances and important details to trust to video instruction.