Keep in mind, although the topics may be lofty, the discussion is intended not only to be insightful, but fun. Remember the words of Oscar Wilde, "Life is too important to be taken too seriously."
For this topic, instead of recommending "On the Nature of Things", which is an ancient, Epicurean poem by Lucretius, that is I think difficult to read (I've tried), I suggested the book, "The Swerve: How the World Became Modern", for some good insights into the question of what is the meaning of life or does life itself have meaning.
Another related shorter source on what gives life meaning are the basic principles of Epicurus, the most important of which being friendship, moderation, and lack of pain, which I mainly learned from Diogenes of Oinoanda, that he inscribed in stone, since most of Epicurus' writings were otherwise distroyed (https://gainweightjournal.com/diogenes-of-oinoanda-the-ancient-secret-to-happiness-discovered-on-a-philosophers-stone-find-out-what-it-is/?fbclid=IwAR1nu2qtXpKf4H4rhCnhys28UT1F1rGgl2XPPWDnDiYyeFZ45wvsF0vNe48).
I also recommended to the group, "The Wisdom of Insecurity" by Allen Watts and "The Gifts of Imperfection" by Brene Brown, and also "Play" by Stuart Brown (no relation, except through reference). Of all these recommendations, the most classic (not counting Epicurus : ) ) and concise is "The Wisdom of Insecurity" of which the Brown books are unintentional, contemporary updates - not sure which of the Brown books I like best - both are excellent... but Watts' is shortest.
Finally, "The Dance of Connection" by Harriet Lerner is also excellent, but like Brene Brown's book, and to a lesser degree "Play", comes at the meaning of life more from a mental health angle, rather than a philosophical one, like Watts, without his also not getting too high-falutin'...