Easter brunch and outfit help?

My boyfriend is taking me to meet his extended family for Easter brunch...I want to make a really good impression on them, and my family has not celebrated Easter since I was like 6 (we have no religious affiliation). I wanted to make something to contribute food-wise to the brunch, what kind of simple dishes are normally on an Easter menu? and are you supposed to dress up, I know that patels and spring colors are appropriate but I wasn't sure how dressy to take it? Thanks