I told my dad that i want to be a sign language teacher and...?

You should be a teacher. But understand that you will have a side business. All teachers do. Two of my sisters are teachers. One is a Lawyer and one is a Realtor. They go hand in hand. Teaching for the love of it and the insurance and other benefits. The other for the money. So you can make both Mom and Dad happy. In the end it's up to you. But I'll tell you right now that you won't make anything off of being just a teacher.