If you want to become an LPN, then begin school and go for it. With your experience as a CNA, you're already familiar with many of the duties of an LPN. You already "know your way" around, have "people experience", and that's a huge headstart. You'll find many of the students in your class (at least the smart ones) will look to you for guidance and leadership.
I received my LPN 48 years ago in the Army, and have used it sporadically since then. I retired 10 years ago and moved from AZ to rural VA. After ten years of substitute teaching and working with local high school athletics, one of the coaches heard me mention that I had an LPN license. The head school nurse then called, asked me if indeed I was licensed, and told me about the shortage of substitute nurses for our school system. I have now applied for and received my VA license, completed my state school orientation, updated my CPR certification, and will begin in-school orientation in the new year. I was able to fill a need, find a job that I enjoy, and no one ever had an issue with my age of 70. Quite the contrary, they considered my age as experience.
And for those who ask, retirement was boring!