Basic yoga can be practised practically anywhere. If you've got enough space for a mat and 30 minutes of free time.
It is very important before you start practising yoga on your own that you get some proper training either at a group yoga school or preferably with a private yoga teacher. You could injure yourself quite easily if you don't have someone to demonstrate the poses (or asanas) and make sure you are performing them correctly.
Breathing is critically important in yoga. Ideally the poses and movements you hold should be performed slowly whilst breathing in a slow, deep and controlled way. When you first start yoga you will probably find this very difficult as you will be using muscles you probably didn't even know you had!
There are many different poses you can hold in yoga (hundreds!). These range from some very easy basic yoga poses through to some fiendishly difficult poses that can take years of dedicated hard work to master.
Yoga is a great form of exercise for people of all ages. It's calming and centering effects are well known and there are tons of resources available to help you progress through from basic yoga on to more advanced forms of yoga.
Best of all, when you are feeling confident practising yoga on your own, you can do it practically anywhere and it's free!