i was shocked

Usually every friday, we have chruch meeting but yesterday, the meeting was cancelled. There was conversation between church members. I was shocked and surprised when i heard that i need to be a sunday school teacher for the first graders. For that moment i was wondering that why did people chooe me ? and they should know that i have barrier in english. I told them i can't do it but they convince to do and i will get extra help from someone to explain to kids if they don't understand anything. Church members also told me that it will help me to speak very well. I will have less fear to speak with someone.
I think that whatever they said it is true but i am not a brave person to stand infront of evryone. let see... how am i going to do tomorrow? i hope i do well