A meaningful life for me to be honest is one that you enjoy more than anything else. There are billions of us on the planet and it is so easy to place meaning in the objective sense rather than the personal one. If someone genuinely helps others then that is meaning, contributing to the world, achievements of note are meaningful as well. In the personal sense, just enjoying life sensibly is all that really matters to me because we are born and then we die in the simplest terms.
If we enjoy our life, with friends and good times and memories then that is all that matters. You can die at any point so for true meaning in life, being happy and comfortable in yourself, always smiling rather than crying and not wasting your time on trivial things or being someone negative. Far too many people spend their time wasting it, i am probably guilty of that as well. But that is not in the sense of not achieving anything because i could learn a language instead of playing FIFA tonight, what good is that as an achievement if i get hit by a bus tomorrow?
So in the sense of personal meaning, just having positive impacts on other people's lives is all that matters. If you died tomorrow, would anyone miss you? Would not having you in their lives make any difference? Whether it is kids, friends, family or even co workers. If you can have a positive effect on someone else in this world by choice instead of by force then your life has plenty of meaning.