Chance to give an advise to your younger self

My nieces are growing so fast! Inalagaan ko sila nung bata sila, and now they're teens. As much as gusto ko silang sabihan na, "mag-aral muna" I feel like their curiously will still haunt them. They ask me for some advices about having their first relationship. Which I think is good, atleast nag-iisip pa rin sila na alam nilang wala silang alam pa. As a non-committal person na puro fun dates lang, wala akong masabi dahil never pa ko nagka official relationship haha.

My question is, if you could give an advise to your younger self about being in a relationship, what would it be?