Youth.

Yesterday I felt alive.
I spent the evening with my friends, we did what teenagers are supposed to do.
We went out for a beer, we laughed until our cheeks hurt.
Later on, we went to a park and we played like little children.

There was a particular moment, when I was on a swing, in which I looked at the sky full of stars and I could feel the wind on my face and I realized that life is full of little moments that we should enjoy every day.

*** That's very nice (: ***

Youth.

Yesterday I felt alive.
I spent the evening with my friends, acting as though we were teenagers.  what teenagers are supposed to do.
We went for a beer, and we laughed until our cheeks hurt.
Later on, we went to a park and we played around like little children.

There was a particular moment, when I was on a swing, in which I looked at the sky full of stars and I could feel the wind on my face and I realized that life is full of little moments that we should enjoy every day.

Very good. What you originally wrote was fine, and I made some minor changes to make it sound more like common language.