“It kind of took me by surprise.”

Your brother announces that he got engaged. You're a bit surprised because he has only been dating his fiancee for 5 months. Someone asks what you think about it, and you say:

It kind of took me by surprise.

kind of

This is an adverb that means "a little" or "somewhat".

take (someone) by surprise

This means to surprise someone. It's actually more common to use this expression than to say "it surprised me".