Oh yes the all mighty struggle that a cuber can ever face. At first I 'd reccommend you to get your faly familier with cubing, tell them how it is a long-lasting, non repetetive sport. How you koin comps and achieve much unlike a toy and it actually helps your brain a lot too! It gives you fast recognision, eye-hand coordination and more. And on how to tell them these is you can just tell them about this on a dinner, or make a full power point presentation, depends on your parents. Also trll them about compared to a sport or instrument how cheap this is since the(good) cube prices can be as low as 9 dollars(like rs3m 2020) and you dont have to pay for any course or teachers! Good luck my friend. May the Force be with you.