Hey there, letters can be sometimes complicated, but I think just writing down your thoughts and just mixing them into sentences would be fine. I have a couple of sentence starters for you.
Hello dad, I’ve been spending the holiday at ____.
Wassup! Days have been great! I’ve been spending the holiday at ___.
Hey dad! It’s been a great time at ____.
Sentence conclusions.
xoxo, ___
In great regards, ____
From your son/daughter ____
A full letter for you:
Hey dad. The last holiday has been great. I went to ____. There’s been fantastic things there that I’ve found. For example, I saw ____, ____, ____. I really hope to see you soon. I think you should maybe go there too!
love, ____