I am not expert when it comes to writing but I do want to talk about what I learned by writing mine.
Write about where you and/or where your parents are from. In the beginning of my paper, I talked about my background. When writing a piece about yourself, always start with the very beginning. You want to give the reader context. You could even talk about your culture as well if you like.
Talk about any hurdle you have had to overcome. This is extremely important because you need to show the reader that you have faced hardships but have shown adversity. However, be careful to not sound like you are bragging or comparing yourself to another person.
I know I said to not to brag necessarily but so not be afraid to talk about your accomplishments in an academic sense. Now, do not go overboard with it because this is not a resume. However, if you could work it in to the main topic of the essay, that would be a good thing. The main thing here is just to incorporate it in a smooth way.
Make sure the essay matches the thesis. When I had my paper checked, the tutor told me that I should emphasize the main topic of my paper. Like I said, it is not a resume or checklist. It is not meant to a list but rather a coherent story.
With all that said, do not stress about it too much. Try your best! Just remember that if you want to transfer anywhere, remember to always have your drafts checked and reviewed.