Where can I find authentic teachers?
Finding a teacher, any teacher at all, may not be so easy. You may have to travel a great distance. However, it is not at all impossible! Some of these are empowerments ("wangs"), programs which may seem impenetrable or "advanced". However, attending an empowerment or "wang", even if you find you have no idea what is going on, is one way to develop the connection to the teacher. Best is if you can find a "public talk" in which the teacher will give more general teachings.
Yes, but how will I know who is the teacher for me?
You may not know at first and you may not know for some time. It may just take your deciding to make a commitment and to leave it at that. As His Holiness Penor Rinpoche mentions in his teaching on this site, if you see "excellent" and "noble" qualities in the teacher and if the teacher is part of an unbroken lineage, then those are qualities of the teacher you would want to select. Sometimes when you meet a teacher you may just have the sense that this is the kindest person you ever met. Other times you may have a feeling that this is someone you met before. And sometimes you won't have any feelings about it at all but can see that what the teacher is saying is true. It is said: "Not the teacher but the teachings." When you have met an authentic teacher, that teacher will reflect either what you profoundly know to be true or what you can scientifically examine and find to be true. In fact, the Buddha himself told his students not to just take everything he said as the truth but to test the truth of his teachings for themselves. So you must simply decide for yourself with whom you wish to study.
I've met a teacher, but don't know what to do next!
If you have met a teacher you like, but have not yet been given any practices to do, you might try just sitting every morning on a cushion for 1/2 hour. You don't have to do anything out of the ordinary, just sit and let your mind be calm. Try and make a special spot to do this; you can put a flower on a table in your room and sit gazing at it. Calm your mind by gently focusing on the flower, your breath or by saying the mantra of compassion, "Om Mani Peme Hung," over and over again to yourself. Try not to focus too much on your breath or the mantra or the flower; don't forget the room. Sit up straight, keep your eyes half open, your lips barely parted and breathe through your mouth rather than through your nose. Don't worry if your mind is full of activity; just let your thoughts be without following them if you can. There are many books which describe meditation practice in detail, you might try using some of the techniques that are available in published form. At the end of your session, remember how you felt when you were in the presence of your teacher and then dedicate any goodness that comes out of your practice to all who are suffering in the world.