The first Bible verse that I learned as a very young child was John 3:16. It served me well, but my mother is a Protestant convert to Catholicism. I am glad to be reminded of this because now I will teach it to my grandson who lives near me and who I take care of frequently.
“For God so loved the world, that he gave his only begotten Son, so that whosoever believeth in Him shall not perish but shall have everlasting life."
I don’t know if that is the KJV rather than the Catholic Bible version, but that is what I will teach my grandson because I understood it at four years of age - probably because at that point I had been attending mass with my parents for my entire life although according to my parents I thought that the priest was St. John because the Parish was St, John. The priest would greet everyone as they left the church, and I would say to him, “Goodbye, St. John,”. According to my parents, the priest would laugh every time.