I'm thinking of applying for a job as a bank teller, but don't know much about it - do you know what they do?
he is an employee of a bank who deals directly with customers.
In what way do they deal with customers? 
In some places, this employee is known as a cashier so they handle the customer money.
Oh, I see!  So they cash checks for them, and deposit their money into their account?  That sounds interesting!
Yes i bet is a really fun job i really hope you get it
Thanks!  What kind of education would be required? 
Most teller jobs need experience with handling cash and a high school diploma. so you would have to have some expirience in the field