If you are new to yoga, please find a qualified instructor to take you through the asanas correctly. If you are not able to get out then online help is an option but please ensure they are qualified to guide you. I am happy to recommend Dee (aka Yogaman) – just drop me a line and I will put you in touch.
The physical aspect of yoga is centered around Asanas. These poses are generally are stretching exercises but also include some balance, strength and relaxation. There are poses in where you are standing and others were you are seated or inverted. Sometimes you bend and other times you twist or spread. Surya Namaskar (sun salutation) consists of 12 asanas (poses) and is a perfect start for beginners.