When beginning yoga, you first need to make sure that you pick out a yoga mat that is good quality. The poses you will be doing mostly involve sitting down, lying down, or kneeling, so you need to be comfortable.
You need to wear the right clothes as well. Tight outfits will not be comfortable; go with something loose instead.
Focus is highly important. When doing your poses, you need to focus rather than compete with anyone else. You can do things at your own pace if your instructor goes too fast for you.
As well, sometimes pain is a part of yoga. When you experience pain during a certain pose or move, it can simply mean that you need to work that part of your body more. However, you do need to be aware of more extreme pain.