Year 12s: what will be the first way you research your future options? >>

Currently in my first year and plan on doing biochem/biomed

I plan on doing biochemistry or biomedical science in university and I'm an unsure what 'extras' I should be doing. When I asked my university co ordinator, she said that i should be able to find some organisations online for work experience and various other kinds of things I could be doing. I am still unsure as to where to start. I plan on applying for Cambridge and want to do as much as I can.
My friend went there and told me that Cambridge want students that are passionate about their courses and they want evidence if this passion outside of college time.

Does anyone know of any organisations related to chemistry or biology that have any schemes or programmes running or if they have work placements? I would really appreciate it. Thanks.