Do you have to have some background in Buddhism to attend?
Although it would be helpful, it is not necessary to have any background in Buddhism.
Will I learn about meditation on Sunday teachings?
On occasion there are teachings about meditation depending on the text being studied at the time. The students do not generally practice silent calm abiding together at the temple. However, the students practice Chenrezig visualization and contemplate verses to develop compassion on Monday nights. If you are interested in learning calm abiding meditation, visit Study Buddhism by Dr. Alexander Berzin.
Why do people bow when the teacher sits on his chair?
Out of great respect for the precious teacher and the precious dharma that liberates, the students stand up when the teacher enters the temple, and they make three prostrations directed to the teacher, the Buddha, the Dharma, and the Sangha. Newcomers who are uncomfortable making prostrations can remain standing while the other students prostrate.