The beginners classes are classes that have minimal chance of injury. Not that you should hurt yourself in any class, but these classes are designed to accommodate anyone. Don't worry if you find some of the poses challenging. Just do as much as you can without forcing yourself. Listen to your body and work with what you have on each given day.

Some of the classes are labelled into seasons. This doesn't mean that if it says it's a Spring time class and you are in Autumn that you can't do the class. That is when the class will be the MOST beneficial, but if you are having an issue with something to do with your Liver or Gall Bladder (flexibility, lack of patience - anger, joint problems, eye sight, etc.) then you can do the Spring/Wood element class (whatever time of year). It's a great idea to do a well rounded practice of yoga with a little bit of every season throughout the year. Every class has a little bit of every season in it anyway. The only thing you may want to be aware of is not to do too many Summer/fire classes in the winter and not too many Winter/water element classes in the Summer. You can do them, but make sure the next class you do is for the other season etc.