explain the use of be going to and will in this dialogue.

maxim: Look at this, Vera! There's a dance competition.
vera: I'm going to enter it!
maxim: Are you going to dance with me?
vera: No, I'm not... Nikita will be my partner. You were late for the competition last time.
maxim: I won't be late this time. We're going to win! ПОМОГИТЕ НЕ ПОНЯЛ НЕЧЕГО ЧТО НАДО СДЕЛАТЬ   !!!!!!!!! ПЛИЗ