Here is some useful language you can use when writing a self-introduction:
I love …
I’m a …/I …
I used to …
Recently …/Last year …
When I’m not …, I …
For example:
I love gardening and learning about nature.
I water and take care of my plants nearly every day.
I used to play the saxophone every day when I was in high school.
I recently won a flower competition and felt very happy.
When I’m not gardening, I enjoy spending time with my friends and family.