Its good that you are starting early. As far as contacting a MALO, ALO, BGO, etc. Its tricky. They are very busy and really only focused on their current candidates. I emailed mine back in soph year. Took a month for him to respond, but he was very informative. Nothing is wrong with contacting him/her early, shows interest. But dont take any offense if they dont respond or reply late. Just introduce yourself, and say you look forward to working with him/her within the coming years.