If you want to go somewhere in a city and you don't have a car or don't want to catch a bus, you take a taxi. Taxi cabs are cars, usually painted a special colour and with a sign on them, that can be hired. The taxi driver will drive you where ever you want to go as long as you pay them.
A taxidermist is someone who takes the skins of dead animals and mounts them into realistic poses, for display.
A teacher is someone who helps other people learn about new things. In a school, a teacher teaches students how to read and write and how to do maths. As children get older their teachers educate them about more complicated things.
Bank tellers are people who work in a bank directly with customers. You queue up to talk to them, and they can do simple banking transactions for you, like deposit or withdraw money. Modern banks prefer you use an automatic teller machine or the internet instead of coming into the bank.