Student assistant in a science laboratory?

I'm going to begin working as a student assistant a college science lab. I'm a little worried on what to expect and what skills I should have. I'm actually an incoming high school senior and was given the oppurtunity to work in the lab for the summer. It is a position undergrad and grad students apply for so I am a bit intimidated and worried about working there...I've always had a love for all sciences and am interested in what this will teach me.