Here is an example informal letter about yourself:
Dear friend,
How are you? I hope this letter finds you well. I thought I'd take some time to tell you a little bit about myself.
My name is [your name]. I was born in [the year your born] and have been learning ever since.
In my free time, I enjoy reading, learning new things, and having interesting conversations. My favorite books are science fiction stories and the future. I find them fascinating.
I hope this gives you a quick glimpse into my life! I'd love to hear back from you and learn more about your interests and experiences too. Drop me a line anytime.
Sincerely,
[your name]