He is coming over Saturday night.?

My neighbour who i like and everytime we talk he smiles and goes red is coming oer for dinner saturday ngiht. Along with his famly and another family. We are going swimming and having dinner. I like him but i am 1 year older than him. What should i wear and how should i have my hair like neat or beachy and messy. And how do i send him the right messages that i like him and wnat a relationship? I am a shy girl and i am not the one to just completyly come out and say i like you..