Tú vs Usted

In spanish there are two ways  to ask people something. One is to say  tú= informal and one is Usted= formal. 
Tú can also translate to english as "you". You only use tú to talk to a friend, or people who are younger than you, or people who are close to you and they are about your age.
Usted (ud) means  sir/mam in english. You use Ud when you're talking to a older person, Like your teacher, your mom/dad, and their friends. If you do not know the person or you are unsure of their age, use ustead.
For example:

 

Now let try out this practice. 
 Ask each of the following people their names and how they feeling today in spanish. Remember tú v.s Usted 

When you go a class and you want to introduce yourself to a spanish teacher. Watch a video of us in class trying to introduce to a spanish teacher