The dentist is doing you a favor, not the other way around, so you shouldn't expect to paid. Also, dress professionally. Remember, they don't call it 'shadowing' for nothing - you are there to observe, and not just the procedures the dentist performs. As Dr.Smiley-OR stated, try to watch the assistants and staff. See how the office functions, the routines, the dynamics of the staff, and so on. If you return you might be able to develop a nice rapport with some of the assistants or hygienists, and if so, ask them what they think are the makings of a good dentist and boss (remember, as a practitioner you will not only have to have good clinical skills but you will need good people/managerial ones as well). Also, try to stay out of the way, don't gasp or freak out if something startles you (as this will upset the patient). Try to let the dentist initiate conversation if he/she is working on a patient (or in other words speak when it's appropriate). Have fun! 👍