It’s polite yoga etiquette to position yourself towards the back of the room if you think you may end up doing more advanced versions of the offered poses. That way you won’t distract other students and turn the class into a spectator endeavor. If you are working with an injury, let the teacher know that you may modify poses to take care of yourself. Teachers keep a particular eye on students with injuries, especially if they’re new; you may even get some additional hands-on adjustments by creating a friendly rapport with the teacher ahead of time.
If you’ve been traveling, there’s a good chance you’ve been sitting too much so be sure to sit up on a blanket, placing your sitting bones (or ischial tuberosities) at the very front of the blanket and crossing your legs comfortably in front of you. This will help maintain the lumbar curve in your back and allow you to sit up straight. A straight spine not only encourages alignment of the whole body but makes room for the lungs to expand fully, thereby oxygenating the brain and the blood. It also allows energy to flow freely from the sacrum out through the crown chakra at the top of the head, thus connecting your personal energy to the greater energy in the universe.
Take some time before class begins to acclimate to the new space: keep your eyes open and softly focused on something about 10 feet in front you, breathe slowly and fully, and allow your physical and energetic bodies to settle. Closing the eyes requires trust and this can take some time when in an unfamiliar place. As you get comfortable, gradually shift your mental focus from the outer edges of your body to the inner spaces. When you’re ready, close your eyes on an inhale and continue mindful breathing. Gently tone your pelvic floor and your lowest abdominal muscles (right above the pubic bone) to help ground your body and allow your breath to ascend all the way up into the collar bones. As you feel your pelvis and legs subtly sink into the floor, you can then expand your inner chamber, your subtle inner energy that connects you to the vast energy source all around us.