hello community members i am new and i need help on grand theft auto five

hello community members to all new old or returning members as my first time posting a question here please i respectfully ask how do i get past story mode? i own an xbox how can i get past story mode specifically where it tells you to push a button called
r and the down button. on my controller which is the xbox one the rt and rb and lt and lb is the only buttons i can find in addition to the sync button and xbox button and x y a b buttons. you get my point is there a way i can complete this cause i am completely
stuck on the very beginning of the game and haven't even tried multiplayer hopefully i get useful answers and any one who come across this has a solution thank you for reading and i hope for useful solutions.

:)