Exercise & diets ! Any suggestions !?

Delia • Im 18 my boyfriend is 24 . We are very much in love . <3
My boyfriend and I have been eating out waaaay too much ! I feel like I've been gaining tons of weight ! I really want to start a diet and exercise routine but i want to do it with my boyfriend that way we can get motivated by each other . Any suggestions on couple exercise routines and diets ? (: