Let's use a hyphen:
It is a cliche to say "it's an adventure." I think that is the slogan of the American national Guard, isn't it? Anyway, it is a cliche. Try to think of a more unique word...
In that second paragraph, I think a dash would work better than that colon.
It has to be a place where I can feel like a part of a family.
I think this is a little to generic. To improve, I think you should focus more on nursing concepts and show that you are already reading a lot of articles in nursing journals. Also, google this: nursing patterns of knowing, porter
It will be great if you revise some of this to share your greatest interests in the field of nursing... specializations that interest you, or your philosophy of nursing.
know a degree from your college will open many doors for me and launch my career.
Stuff like this does not help. It is obvious, general, and not very meaningful. That is why I think you should give this essay a THEME based on the nursing concepts that interest you. Read a nursing article in a professional journal right now for inspiration! You actually only need to read the article's intro and conclusion if you want to get ideas.