Answer:
When writing a letter, you must remember to write the date, the person's name and an opening (Dear ...)
Ex.
4/18/2022
Dear Kirito,
Happy birthday! (this is an example of a letter) I hope you are doing good. It's really cold here in Seattle. Can't believe you're (example of grammar, your and you're) 13 already. That means you'll be extra grumpy, lol;). I wish your birthday is as sweet as you are. Stay safe and I hope to see you soon!
Love, Mousey
(These names, dates and places are made up)
Anyways, I hope I was able to help you answer your question. I am only in 7th grade, therefore, I am not the smartest person to ever exist, but please tell me if I did something wrong. Have a great day:)