When joining a group session, think about rule number 1: keep you eyes over your yoga mat.
It doesn’t matter how bendy or strong fellow yoga students are. Are they able to hold a certain asana till 5 breaths, or can they fully forward fold.
It is your practice. Your journey. You are the one who matters most to yourself. Do not direct your attention from that. Would your monkey mind lead you away from your mat, then try to tame it and return. It is an excellent way to train your attention, and focus on nothing less than yourself.
When your attention is inward, bring your awareness to your body. Feel your fingertips spreading on the ground, your spine’s lengthening, feel your chest expanding with each inhale.
Train your attention while practicing asanas. And remember, what happens on your mat, will affect you life off the mat.