If you are genuinely interested in helping young people, don't say anything like this. In the context of your particular socio-cultural environment, this is a viable and much better position, "Each child is different. I am here to teach them life skills. I hope that whenever they have a problem, they feel that they can trust me enough to come and talk to me about it." See this extract from an article in "Psychology Today": "Parents usually become concerned when their teenager falls in love in high school. Perhaps they don’t want their adolescent to get so serious so young. Perhaps they don’t trust, feel comfortable with, or approve their son or daughter’s chosen love. Perhaps they suspect some mistreatment might occur. Perhaps they fear the increased likelihood of sexual involvement. Of course, they can try prohibiting the relationship, but in doing so their opposition can intensify the attraction they are trying to stop. In most cases, they gain more influence with the young people by befriending the relationship, welcoming them to hang out in their home when parents are present, providing an empathetic response and listening ear when the relationship hits a hard spot, and making their wishes known about how sexual activity is to be safely managed — because in most adolescent in-love relationships, sexual intimacy is sought to affirm emotional intimacy that the couple feels. In general, I believe it is better for parents to count themselves in with support than to factor themselves out with opposition. Parents can be useful sounding boards as the young people try to sort out the complexities and perplexities of love." (to be continued in the next frame in view of the word limit per frame)

(continuing from above) "What parents may not appreciate are a number of positives that come from these in-love relationships. For example, by focusing on each other and time together, the couple often excuses themselves from a lot of the wilder partying and trouble making that goes with high school socializing. By experiencing a level of caring with each other that is far deeper than that of casual dating relationships, the couple socially matures in ways many of their less involved peers do not. By trying to honor the love they feel through treating each other sensitively and well, they can learn loving skills for later relationships." Quoted from "Adolescence and Falling in Love" by Carl Pickhardt, "Psychology Today" (https://www.psychologytoday.com/blog/surviving-your-childs-adolescence/201206/adolescence-and-falling-in-love)

Too of your questions in a row, random! But normally, "Don't fall in love too early" would be perfectly fine I think, I've heard the same phrase said by parents and teachers.